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  • 1.
    Absil, Oliver
    et al.
    Université de Liège, Belgium.
    Mawet, Dimitri
    California Institute of Technology/Jet Propulsion Laboratory, USA.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Carlomagno, Brunella
    Université de Liège, Belgium.
    Christiaens, Valentin
    Universidad de Chile, Chile.
    Defrère, Denis
    Université de Liège, Belgium.
    Delacroix, Christian
    Cornell University, USA.
    Femenía Castellá, Bruno
    W. M. Keck Observatory, USA.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Girard, Julien
    European Southern Observatory, Chile.
    Gómez González, Carlos A.
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Hinz, Philip M.
    University of Arizona, USA.
    Huby, Elsa
    Université de Liège, Belgium.
    Jolivet, Aissa
    Université de Liège, Belgium.
    Matthews, Keith
    California Institute of Technology, USA.
    Milli, Julien
    European Southern Observatory, USA.
    Orban de Xivry, Gilles
    Université de Liège, Belgium.
    Pantin, Eric
    Université Paris Diderot, France.
    Piron, Pierre
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Reggiani, Maddalena
    Université de Liège, Belgium.
    Ruane, Garreth J.
    California Institute of Technology, USA.
    Serabyn, Eugene
    Jet Propulsion Laboratory, USA.
    Surdej, Jean
    Université de Liège, Belgium.
    Tristram, Konrad R. W.
    European Southern Observatory, Chile.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wertz, Olivier
    Université de Liège, Belgium.
    Wizinowich, Peter
    W. M. Keck Observatory, USA.
    Three years of harvest with the vector vortex coronagraph in the thermal infrared2016In: Ground-Based and Airborne Instrumentation for Astronomy VI: 26-30 June 2016, Edinburgh, United Kingdom / [ed] Christopher J Evans, SPIE - International Society for Optical Engineering, 2016, Vol. 9908, p. 1-14, article id 99080Q-1Conference paper (Refereed)
    Abstract [en]

    For several years, we have been developing vortex phase masks based on sub-wavelength gratings, known as Annular Groove Phase Masks. Etched onto diamond substrates, these AGPMs are currently designed to be used in the thermal infrared (ranging from 3 to 13 μm). Our AGPMs were first installed on VLT/NACO and VLT/VISIR in 2012, followed by LBT/LMIRCam in 2013 and Keck/NIRC2 in 2015. In this paper, we review the development, commissioning, on-sky performance, and early scientific results of these new coronagraphic modes and report on the lessons learned. We conclude with perspectives for future developments and applications.

  • 2. Absil, Olivier
    et al.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Carlomagno, Brunella
    Christiaens, Valentin
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez Gonzales, Carlos
    Habraken, Serge
    Jolivet, Aïssa
    Piron, Pierre
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Absil, Pierre-Antoine
    Boccaletti, Anthony
    Baudoz, Pierre
    Defrère, Dennis
    Milli, Julien
    Surdej, Sean
    Optimized, high performance vortex coronagraphs for E-ELT instruments2014Conference paper (Refereed)
  • 3. Absil, Olivier
    et al.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Carlomagno, Brunella
    Christiaens, Valentin
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez Gonzales, Carlos
    Habraken, Serge
    Jolivet, Aïssa
    Piron, Pierre
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Absil, Pierre-Antoine
    Boccaletti, Anthony
    Baudoz, Pierre
    Defrère, Dennis
    Milli, Julien
    Surdej, Sean
    Reaching the diffraction limit with the vortex coronagraph2014Conference paper (Refereed)
  • 4. Absil, Olivier
    et al.
    Mawet, Dimitri
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Surdej, Jean
    Absil, Pierre-Antoine
    Carlomagno, Brunella
    Christiaens, Valentin
    Defrere, Denis
    Gonzalez, Carlos Gomez
    Huby, Elsa
    Jolivet, Aissa
    Milli, Julien
    Piron, Pierre
    Catalan, Ernesto Vargas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Van Droogenbroeck, Marc
    The VORTEX project: first results and perspectives2014In: Adaptive Optics Systems IV, 2014, article id 91480MConference paper (Refereed)
    Abstract [en]

    Vortex coronagraphs are among the most promising solutions to perform high contrast imaging at small angular separations from bright stars. They feature a very small inner working angle (down to the diffraction limit of the telescope), a clear 360 degree discovery space, have demonstrated very high contrast capabilities, are easy to implement on high-contrast imaging instruments, and have already been extensively tested on the sky. Since 2005, we have been designing, developing and testing an implementation of the charge-2 vector vortex phase mask based on concentric sub-wavelength gratings, referred to as the Annular Groove Phase Mask (AGPM). Science-grade mid-infrared AGPMs were produced in 2012 for the first time, using plasma etching on synthetic diamond substrates. They have been validated on a coronagraphic test bench, showing broadband peak rejection up to 500: 1 in the L band, which translates into a raw contrast of about 6 x 10(-5) at 2 lambda/D. Three of them have now been installed on world-leading diffraction-limited infrared cameras, namely VLT/NACO, VLT/VISIR and LBT/LMIRCam. During the science verification observations with our L-band AGPM on NACO, we observed the beta Pictoris system and obtained unprecedented sensitivity limits to planetary companions down to the diffraction limit (0 : 1 0 0). More recently, we obtained new images of the HR 8799 system at L band during the AGPM first light on LMIRCam. After reviewing these first results obtained with mid-infrared AGPMs, we will discuss the short-and mid-term goals of the on-going VORTEX project, which aims to improve the performance of our vortex phase masks for future applications on second-generation high-contrast imager and on future extremely large telescopes (ELTs). In particular, we will briefly describe our current efforts to improve the manufacturing of mid-infrared AGPMs, to push their operation to shorter wavelengths, and to provide deeper starlight extinction by creating new designs for higher topological charge vortices. Within the VORTEX project, we also plan to develop new image processing techniques tailored to coronagraphic images, and to study some pre- and post-coronagraphic concepts adapted to the vortex coronagraph in order to reduce scattered starlight in the final images.

  • 5. Absil, Olivier
    et al.
    Mawet, Dimitri
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Surdej, Jean
    Absil, Pierre-Antoine
    Carlomagno, Brunella
    Christiaens, Valentin
    Defrère, Denis
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Girard, Julien
    Gomez Gonzalez, Carlos
    Hinz, Philip
    Huby, Elsa
    Jolivet, Aïssa
    Milli, Julien
    Pantin, Eric
    Ruane, Garreth
    Serabyn, Eugene
    Van Droogenbroeck, Marc
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wertz, Olivier
    An update on the VORTEX project2015In: Techniques and Instrumentation for Detection of Exoplanets VII, 2015, Vol. 9605Conference paper (Refereed)
    Abstract [en]

    In this talk, we will review the on-going activities within the VORTEX teamat the University of Liège and Uppsala University. The VORTEX project aimsto design, manufacture, test, and exploit vector vortex phase masks madeof sub-wavelength gratings (aka the Annular Groove Phase Mask, AGPM)for the direct detection and characterization of extrasolar planets. This talkwill specifically report on the commissioning of several AGPMs on infraredcameras equipping 10-m class telescopes, including the VLT, the LBT andthe Keck. We will describe the in-lab and on-sky performance of the AGPMs,and discuss first scientific observations. We will also report on the lessonslearned from the on-sky operation of our vortices, and discuss ways toimprove their performance. The potential of our coronagraphic devices inthe context of future extremely large telescopes and space missions will alsobe addressed.

  • 6.
    Almandoz-Gil, Leire
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Welander, Hedvig
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ihse, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Khoonsari, Payam Emami
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Musunuri, Sravani
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Lendel, Christofer
    KTH Royal Inst Technol, Dept Chem, Stockholm, Sweden.
    Sigvardson, Jessica
    BioArctic AB, Stockholm, Sweden.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Kultima, Kim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Corrigendum to “Low molar excess of 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote oligomerization of alpha-synuclein through different pathways” [Free Rad. Biol. Med. (2017) 421–431]2018In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 117, p. 258-258Article in journal (Refereed)
  • 7.
    Almandoz-Gil, Leire
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Welander, Hedvig
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ihse, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Khoonsari, Payam Emami
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Musunuri, Sravani
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Lendel, Christofer
    KTH, Royal Institute of Technology, Sweden.
    Sigvardson, Jessica
    BioArctic AB, Sweden.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Kultima, Kim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Cancer Pharmacology and Computational Medicine.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Low molar excess of 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote oligomerization of alpha-synuclein through different pathways2017In: Free Radical Biology & Medicine, ISSN 0891-5849, E-ISSN 1873-4596, Vol. 110, p. 421-431Article in journal (Refereed)
    Abstract [en]

    Aggregated alpha-synuclein is the main component of Lewy bodies, intraneuronal inclusions found in brains with Parkinson's disease and dementia with Lewy bodies. A body of evidence implicates oxidative stress in the pathogenesis of these diseases. For example, a large excess (30:1, aldehyde:protein) of the lipid peroxidation end products 4-oxo-2-nonenal (ONE) or 4-hydroxy-2-nonenal (HNE) can induce alpha-synuclein oligomer formation. The objective of the study was to investigate the effect of these reactive aldehydes on alpha-synuclein at a lower molar excess (3:1) at both physiological (7.4) and acidic (5.4) pH. As observed by size-exclusion chromatography, ONE rapidly induced the formation of alpha-synuclein oligomers at both pH values, but the effect was less pronounced under the acidic condition. In contrast, only a small proportion of alpha-synuclein oligomers were formed with low excess HNE-treatment at physiological pH and no oligomers at all under the acidic condition. With prolonged incubation times (up to 96 h), more alpha-synuclein was oligomerized at physiological pH for both ONE and HNE. As determined by Western blot, ONE-oligomers were more SDS-stable and to a higher-degree cross-linked as compared to the HNE-induced oligomers. However, as shown by their greater sensitivity to proteinase K treatment, ONE-oligomers, exhibited a less compact structure than HNE-oligomers. As indicated by mass spectrometry, ONE modified most Lys residues, whereas HNE primarily modified the His50 residue and fewer Lys residues, albeit to a higher degree than ONE. Taken together, our data show that the aldehydes ONE and HNE can modify alpha-synuclein and induce oligomerization, even at low molar excess, but to a higher degree at physiological pH and seemingly through different pathways.

  • 8.
    Andersson, Per Ola
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. FOI Swedish Def Res Agcy, CBRN Def & Secur, S-90182 Umea, Sweden.; Mol Fingerprint Sweden AB, Eksatravagen 130, S-75655 Uppsala, Sweden.
    Viberg, Pernilla
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Mol Fingerprint Sweden AB, Eksatravagen 130, S-75655 Uppsala, Sweden.
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics. Mol Fingerprint Sweden AB, Eksatravagen 130, S-75655 Uppsala, Sweden.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences. Mol Fingerprint Sweden AB, Eksatravagen 130, S-75655 Uppsala, Sweden.
    Nanocrystalline diamond sensor targeted for selective CRP detection: An ATR-FTIR spectroscopy study2016In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 408, no 14, p. 3675-3680Article in journal (Refereed)
    Abstract [en]

    Protein immobilization on functionalized fluorine- terminated nanocrystalline (NCD) films was studied by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy using an immobilization protocol developed to specifically bind C-reactive protein (CRP). Using an ATR- FTIR spectroscopy method employing a force-controlled anvil-type configuration, three critical steps of the ex situ CRP immobilization were analyzed. First, the NCD surface was passivated by deposition of a copolymer layer consisting of polyethylene oxide and polypropylene oxide. Second, a synthetic modified polypeptide binder with high affinity to CRP was covalently attached to the polymeric film. Third, CRP dissolved in aqueous buffer in concentrations of 10–20 μg/ mL was added on the functionalized NCD surface. Both the amide I and II bands, due to the polypeptide binder and CRP, were clearly observed in ATR-FTIR spectra. CRP amide I bands were extracted from difference spectra and yielded bands that agreed well with the reported amide I band of free (non-bonded) CRP in solution. Thus, our results show that CRP retains its secondary structure when it is attached to the polypeptide binders. Compared to previous IR studies of CRP in solution, about 200 times lower concentration was applied in the present study. 

  • 9.
    Bergström, Joakim
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Näsström, Thomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Wahlberg, Therese
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Effects of lipid peroxidation metabolites on alpha-synuclein aggregation2009Conference paper (Refereed)
  • 10.
    Björnängen, Peter
    et al.
    Micronic Laser Systems AB, Sweden.
    Ekberg, Mats
    Micronic Laser Systems AB, Sweden.
    Öström, Thomas
    Micronic Laser Systems AB, Sweden.
    Fosshaug, Hans
    Micronic Laser Systems AB, Sweden.
    Karlsson, Johan
    Micronic Laser Systems AB, Sweden.
    Björnberg, Charles
    Micronic Laser Systems AB, Sweden.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    DOE Manufacture with the DUV SLM-based Sigma7300 Laser Pattern Generator2004Conference paper (Refereed)
  • 11.
    Cai, Yixao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Almandoz-Gil, Leire
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Österund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    ATR- FTIR spectroscopy study of oxidative modification of the a-synuclein secondary structure2013Conference paper (Refereed)
  • 12.
    Cai, Yixiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Edin, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Jin, Zhe
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Physiology.
    Alexsson, Andrei
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Rheumatology.
    Gudjonsson, Olafur
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Liu, Wei
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Rask-Andersen, Helge
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Li, Hao
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Strategy towards independent electrical stimulation from cochlear implants: Guided auditory neuron growth on topographically modified nanocrystalline diamond2016In: Acta Biomaterialia, ISSN 1742-7061, E-ISSN 1878-7568, Vol. 31, p. 211-220Article in journal (Refereed)
    Abstract [en]

    Cochlear implants (CI) have been used for several decades to treat patients with profound hearing loss. Nevertheless, results vary between individuals, and fine hearing is generally poor due to the lack of discrete neural stimulation from the individual receptor hair cells. A major problem is the deliverance of independent stimulation signals to individual auditory neurons. Fine hearing requires significantly more stimulation contacts with intimate neuron/electrode interphases from ordered axonal re-growth, something current CI technology cannot provide.

    Here, we demonstrate the potential application of micro-textured nanocrystalline diamond (NCD) surfaces on CI electrode arrays. Such textured NCD surfaces consist of micrometer-sized nail-head-shaped pillars (size 5 5 lm2) made with sequences of micro/nano-fabrication processes, including sputtering, photolithography and plasma etching.

    The results show that human and murine inner-ear ganglion neurites and, potentially, neural progenitor cells can attach to patterned NCD surfaces without an extracellular matrix coating. Microscopic methods revealed adhesion and neural growth, specifically along the nail-head-shaped NCD pillars in an ordered manner, rather than in non-textured areas. This pattern was established when the inter-NCD pillar distance varied between 4 and 9 lm.

    The findings demonstrate that regenerating auditory neurons show a strong affinity to the NCD pillars, and the technique could be used for neural guidance and the creation of new neural networks. Together with the NCD’s unique anti-bacterial and electrical properties, patterned NCD surfaces could provide designed neural/electrode interfaces to create independent electrical stimulation signals in CI electrode arrays for the neural population.

  • 13.
    Cai, Yixiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Edin, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Li, Hao
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Ordered auditory neuron growth on micro-structured nanocrystalline diamond surface2015Conference paper (Refereed)
  • 14.
    Cai, Yixiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Lendel, Christofer
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Kasrayan, Alex
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Changes in secondary structure of α-synuclein during oligomerization induced by reactive aldehydes.2015In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 464, no 1, p. 336-341Article in journal (Refereed)
    Abstract [en]

    The oxidative stress-related reactive aldehydes 4-hydroxy-2-nonenal (HNE) and 4-oxo-2-nonenal (ONE) have been shown to promote formation of α-synuclein oligomers in vitro. However, the changes in secondary structure of α-synuclein and the kinetics of the oligomerization process are not known and were the focus of this study. Size exclusion chromatography showed that after 1 h of incubation, HNE induced the formation of an oligomeric α-synuclein peak with a molecular weight of about ∼2000 kDa, which coincided with a decreasing ∼50 kDa monomeric peak. With prolonged incubation (up to 24 h) the oligomeric peak became the dominating molecular species. In contrast, in the presence of ONE, a ∼2000 oligomeric peak was exclusively observed after 15 min of incubation and this peak remained constant with prolonged incubation. Western blot analysis of HNE-induced α-synuclein oligomers showed the presence of monomers (15 kDa), SDS-resistant low molecular (30-160 kDa) and high molecular weight oligomers (≥260 kDa), indicating that the oligomers consisted of both covalent and non-covalent protein. In contrast, ONE-induced α-synuclein oligomers only migrated as covalent cross-linked high molecular-weight material (≥300 kDa). Both circular dichroism (CD) and Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy showed that the formation of HNE- and ONE-induced oligomers coincided with a spectral change from random coil to β-sheet. However, ONE-induced α-synuclein oligomers exhibited a slightly higher degree of β-sheet. Taken together, our results indicate that both HNE and ONE induce a change from random coil to β-sheet structure that coincides with the formation of α-synuclein oligomers. Albeit through different kinetic pathways depending on the degree of cross-linking.

  • 15.
    Cai, Yixiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Li, Hu
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Leifer, Klaus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Engqvist, Håkan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Xia, Wei
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Biomineralization on Single Crystalline Rutile: The Modulated Growth of Hydroxyapatite by Fibronectin in a Simulated Body Fluid2016In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 6, p. 35507-35516Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to probe the complex interaction between surface bioactivity and protein adsorption on single crystalline rutile. Our previous studies have shown that single crystalline rutile possessed in vitro bioactivity and the crystalline faces affected the hydroxyapatite (HA) formation. However, upon implantation, a fast adsorption of proteins, from the biological fluids, is intermediated by a water layer towards the biomaterial interface. Thus the effect of protein on the bioactivity must be addressed. In this study, the HA growth dynamics on (001), (100) and (110) faces was investigated in a simulated body fluid with the presence of fibronectin (FN) by two different processes. The surface adhesion of each face before and after FN adsorption, as revealed by direct numerical values, was determined by atomic force microscopy (AFM) based peak force quantitative nanomechanical mapping (PF-QNM) for the first time. The findings suggest the surface energies of FN pre-adsorbed (001), (100) and (110) faces have been enhanced, leading to the subsequent accelerated HA formation. Furthermore, (001) and (100) faces were found to have larger coverage of HA crystals than (110) face at an early stage. In addition, various characterizations were performed to probe the chemical and crystal structures of as-grown biomimetic HA crystals, and in particular, the Ca/P ratio variations at different soaking time points.

  • 16.
    Carlomagno, Brunella
    et al.
    Université de Liège, Belgium.
    Absil, Olivier
    Université de Liège, Belgium.
    Kenworthy, Matthew
    Leiden University, The Netherlands.
    Ruane, Garreth
    California Institute of Technology, USA.
    Keller, Christoph U.
    Leiden University, The Netherlands.
    Otten, Gilles
    Leiden University, The Netherlands.
    Feldt, Markus
    Max-Planck-Institut für Astronomie, Germany.
    Hippler, Stefan
    Max-Planck-Institut für Astronomie, Germany.
    Huby, Elsa
    Université de Liège, Belgium.
    Mawet, Dmitri
    California Institute of Technology, USA.
    Delacroix, Christian
    Cornell University, USA.
    Surdej, Jean
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Brandl, Bernhard R.
    Leiden University, The Netherlands.
    End-to-end simulations of the E-ELT/METIS coronagraphs2016In: Adaptive Optics Systems V / [ed] Marchetti, E; Close, LM; Veran, JP, SPIE - International Society for Optical Engineering, 2016, p. 1-10, article id 990973Conference paper (Refereed)
    Abstract [en]

    The direct detection of low-mass planets in the habitable zone of nearby stars is an important science case for future E-ELT instruments such as the mid-infrared imager and spectrograph METIS, which features vortex phase masks and apodizing phase plates (APP) in its baseline design. In this work, we present end-to-end performance simulations, using Fourier propagation, of several METIS coronagraphic modes, including focal-plane vortex phase masks and pupil-plane apodizing phase plates, for the centrally obscured, segmented E-ELT pupil. The atmosphere and the AO contributions are taken into account. Hybrid coronagraphs combining the advantages of vortex phase masks and APPs are considered to improve the METIS coronagraphic performance.

  • 17.
    Carlomagno, Brunella
    et al.
    Université de Liège, Belgium.
    Absil, Olivier
    Université de Liège, Belgium.
    Ruane, Garreth
    Rochester Institute of Technology, USA.
    Mawet, Dimitri
    California Institute of Technology/NASA Jet Propulsion Laboratory, USA.
    Feldt, Markus
    MPIA, Heidelberg, Germany.
    Hippler, Stefan
    MPIA, Heidelberg, Germany.
    Delacroix, Christian
    Centre de Recherche Astrophysique de Lyon, France.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Université de Liège, Belgium.
    Huby, Elsa
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Surdej, Jean
    Université de Liège, Belgium.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Performance evaluation of mid-IR vortex coronagraphs with centrally obscured segmented pupils2015Conference paper (Refereed)
    Abstract [en]

    In its original design, the E-ELT/Metis instrument envisages a vortex coronagraph in the mid-IR regime for detection and characterization of exoplanets, with a contrast of 1e-4 at 2 lambda/D (~40 mas in L band). The AGPM (Annular Groove Phase Mask) is a vortex phase mask with impressive characteristics: small inner working angle, high throughput, achromaticity. A non-perfectly circular pupil and non-flat input wavefront result in a starlight leakage, degrading the performance of the vortex coronagraph. In this work, we present end-to-end performance simulations using Fourier optical propagation to determine the quality of the starlight rejection obtained with an infrared vortex coronagraph. We first analyse the performance facing E-ELT pupil variations (segmentations, central obscuration, spiders, missing segments), then pointing jitter and random adaptive optics residual phase screens are introduced to derive more realistic performance. Finally, more advanced concepts of the infrared vortex coronagraph are presented, in order to compensate for performance degradation.

  • 18. Carlomagno, Brunella
    et al.
    Delacroix, Christian
    Absil, Olivier
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Jolivet, Aissa
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Piron, Pierre
    Surdej, Jean
    Catalan, Ernesto Vargas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mid-IR AGPMs for ELT applications2014In: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY V, 2014, Vol. 9147, article id 914799Conference paper (Refereed)
    Abstract [en]

    The mid-infrared region is well suited for exoplanet detection thanks to the reduced contrast between the planet and its host star with respect to the visible and near-infrared wavelength regimes. This contrast may be further improved with Vector Vortex Coronagraphs (VVCs), which allow us to cancel the starlight. One flavour of the VVC is the AGPM (Annular Groove Phase Mask), which adds the interesting properties of subwavelength gratings (achromaticity, robustness) to the already known properties of the VVC. In this paper, we present the optimized designs, as well as the expected performances of mid-IR AGPMs etched onto synthetic diamond substrates, which are considered for the E-ELT/METIS instrument.

  • 19. Carlomagno, Brunella
    et al.
    Delacroix, Christian
    Huby, Elsa
    Absil, Olivier
    Mawet, Dimitri
    Jolivet, Aïssa
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Surdej, Jean
    Design and performance simulations of mid-IR AGPMs for ELT/METIS applications2015Conference paper (Refereed)
    Abstract [en]

    The direct detection of exoplanets requires the use of dedicated, highcontrast imaging instruments. In this context, vector vortex coronagraphs(VVCs) are considered to be among the most promising solutions to reachhigh contrast at small angular separations. They feature a small innerworking angle (down to 0.9 lambda/D), high throughput, clear off-axis360° discovery space, and are simple to implement. The AGPM (AnnularGroove Phase Mask) is an implementation of the vortex phase mask, whichprovides achromaticity over an appreciable spectral range thanks to the useof sub-wavelength gratings. The grating profile can be optimized based onthe rigorous coupled wave analysis (RCWA) to achieve a quasi-achromaticphase shift up to a very broad band (L+M band: 3.5-5.1μm). These deviceshave been manufactured onto CVD diamond substrates, using reactiveion etching. In this communication, I will first present the latest RCWAConference 9605: Techniques and Instrumentationfor Detection of Exoplanets VIIR eturn to Contents +1 360 676 3290 · help@spie.org 631simulations performed in the L, M and N spectral bands, and for somecombinations of these bands. The resulting optimized AGPMs could beperfectly integrated in the E-ELT/METIS instrument, which aims at detectingand characterizing exoplanets by direct imaging. The target contrast forMETIS is <1e-4 at 2 lambda/D (~40 mas in L band), which translates into apeak rejection rate of few hundreds for the AGPMs. Secondly, the opticalpropagation within the METIS instrument will be studied to determine theperformances of a vortex coronagraph at the focus of METIS. In particular,the effect of the central obstruction, spiders, missing E-ELT segments,and pointing jitter will be analysed, together with the sensitivity to tip-tilt.Finally, the atmosphere and the AO contributions will be considered toobtain more realistic results.

  • 20. Carlomagno, Brunella
    et al.
    Olivier, Absil
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Delacroix, Christian
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Habraken, Serge
    Jolivet, Aïssa
    Mawet, Dimitri
    Piron, Pierre
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Surdej, Sean
    Design and expected performances ofL, M and N band AGPMs for EELT/METIS.2014Conference paper (Refereed)
  • 21.
    Castellá, Bruno Femenía
    et al.
    W. M. Keck Observatory, USA.
    Serabyn, Eugene
    Jet Propulsion Laboratory, USA.
    Mawet, Dimitri
    California Institute of Technology, USA.
    Absil, Olivier
    University of Liège, Belgium.
    Wizinowich, Peter
    W. M. Keck Observatory, USA.
    Matthews, Keith
    California Institute of Technology, USA.
    Huby, Elsa
    University of Liège, Belgium.
    Bottom, Michael
    California Institute of Technology, USA.
    Campbell, Randy
    W. M. Keck Observatory, USA.
    Chan, Dwight
    W. M. Keck Observatory, USA.
    Carlomagno, Brunella
    University of Liège, Belgium.
    Cetre, Sylvian
    W. M. Keck Observatory, USA.
    Defrère, Denis
    Steward Observatory, USA.
    Delacroix, Christian
    Cornell University, USA.
    Gonzalez, Carlos Gomez
    University of Liège, Belgium.
    Jolivet, Aissa
    University of Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Lanclos, Kyle
    W. M. Keck Observatory, USA.
    Lilley, Scott
    W. M. Keck Observatory, USA.
    Milner, Steven
    W. M. Keck Observatory, USA.
    Ngo, Henry
    California Institute of Technology, USA.
    Reggiani, Maddalena
    University of Liège, Belgium.
    Simmons, Julia
    W. M. Keck Observatory, USA.
    Tran, Hien
    W. M. Keck Observatory, USA.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Wertz, Olivier
    University of Liège, Belgium.
    Commissioning and first light results of an L’-band vortex coronagraph with the Keck II adaptive optics NIRC2 science instrument2016In: Adaptive Optics Systems V / [ed] Marchetti, E; Close, LM; Veran, JP, SPIE - International Society for Optical Engineering, 2016, Vol. 9909, article id 990922Conference paper (Refereed)
    Abstract [en]

    On March 2015 an L'-band vortex coronagraph based on an Annular Groove Phase Mask made up of a diamond sub-wavelength grating was installed on NIRC2 as a demonstration project. This vortex coronagraph operates in the L' band not only in order to take advantage from the favorable star/planet contrast ratio when observing beyond the K band, but also to exploit the fact that the Keck II Adaptive Optics (AO) system delivers nearly extreme adaptive optics image quality (Strehl ratios values near 90%) at 3.7 mu m. We describe the hardware installation of the vortex phase mask during a routine NIRC2 service mission. The success of the project depends on extensive software development which has allowed the achievement of exquisite real-time pointing control as well as further contrast improvements by using speckle nulling to mitigate the effect of static speckles. First light of the new coronagraphic mode was on June 2015 with already very good initial results. Subsequent commissioning nights were interlaced with science nights by members of the VORTEX team with their respective scientific programs. The new capability and excellent results so far have motivated the VORTEX team and the Keck Science Steering Committee (KSSC) to offer the new mode in shared risk mode for 2016B.

  • 22.
    Chitica, N
    et al.
    MATERIALS SCIENCE/MST.
    Daleiden, J
    Bentell, J
    Andre, J
    Strassner, M
    Greek, Staffan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Pasquariello, Donato
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Gupta, Ram
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Hjort, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science.
    Fabrication of tunable InP/air-gap Fabry-Perot cavities by selective etching of InGaAs sacrificial layers1999In: Physica scripta. T, ISSN 0281-1847, Vol. T79, p. 131-134Article in journal (Refereed)
    Abstract [en]

    We report the fabrication of InP/air-gap Fabry-Perot resonant cavities with an improved tunability characteristic achieved through the micromachining of more flexible suspended InP beams. The micromechanical structures are electrostatically actuated. A tuning range of 55 nm is demonstrated for an actuation voltage of 12 V. The low leakage current, of less than 10 µA for a bias of up to 30 V, provides a low actuation power. The tunable air-gap cavities are fabricated by selective wet etching of InGaAs sacrificial layers. An FeCl3 based etchant is used to completely remove the InGaAs material without affecting the thickness of the InP layer. The anisotropy of the etch rate of InGaAs was also investigated and exploited in the micromachining process.

  • 23.
    Darwish, Nasser
    et al.
    Universitat de Barcelona, Spain.
    Moreno, Mauricio
    Universitat de Barcelona, Spain.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Samitier, Josep
    Universitat de Barcelona, Spain.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Surface plasmon resonance using nanocrystaline diamond substrates2010Conference paper (Refereed)
  • 24. Defrere, D.
    et al.
    Absil, O.
    Hinz, P.
    Kuhn, J.
    Mawet, D.
    Mennesson, B.
    Skemer, A.
    Wallace, K.
    Bailey, V.
    Downey, E.
    Delacroix, C.
    Durney, O.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez, C.
    Habraken, S.
    Hoffmann, W. F.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Kenworthy, M.
    Leisenring, J.
    Montoya, M.
    Pueyo, L.
    Skrutskie, M.
    Surdej, J.
    L'-band AGPM vector vortex coronagraph's first light on LBTI/LMIRCam2014In: Adaptive Optics Systems IV, 2014, article id 91483XConference paper (Refereed)
    Abstract [en]

    We present the first observations obtained with the L'-band AGPM vortex coronagraph recently installed on LBTI/LMIRCam. The AGPM (Annular Groove Phase Mask) is a vector vortex coronagraph made from diamond subwavelength gratings. It is designed to improve the sensitivity and dynamic range of high-resolution imaging at very small inner working angles, down to 0.09 arcseconds in the case of LBTI/LMIRCam in the L' band. During the first hours on sky, we observed the young A5V star HR8799 with the goal to demonstrate the AGPM performance and assess its relevance for the ongoing LBTI planet survey (LEECH). Preliminary analyses of the data reveal the four known planets clearly at high SNR and provide unprecedented sensitivity limits in the inner planetary system (down to the diffraction limit of 0.09 arcseconds).

  • 25.
    Defrère, D.
    et al.
    Steward Observatory, USA.
    Absil, Olivier
    University of Liège, Belgium.
    Kuhn, J.
    Jet Propulsion Laboratory, USA.
    Mawet, Dimitri
    European Southern Observatory, Chile.
    Mennesson, B.
    Jet Propulsion Laboratory, USA.
    Skemer, A.
    Steward Observatory, USA.
    Wallace, K.
    Jet Propulsion Laboratory, USA.
    Bailey, V.
    Steward Observatory, USA.
    Downey, E.
    Steward Observatory, USA.
    Delacroix, Christian
    University of Liège, Belgium.
    Durney, O.
    Steward Observatory, USA.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Gomez, Carlos
    University of Liège, Belgium.
    Habraken, Serge
    University of Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Kenworthy, M.
    Leiden Observatory, The Netherlands.
    Montoya, M.
    Steward Observatory, USA.
    Pueyo, L.
    Space Telescope Science Institute, USA.
    Skrutskie, M.
    University of Virginia, USA.
    Surdej, Jean
    University of Liège, Belgium.
    L'-band AGPM vector vortex coronagraph's first light on LBTI/LMIRCAM2014Conference paper (Refereed)
  • 26.
    Delacroix, C.
    et al.
    Université de Liège, Belgium.
    Absil, O.
    Université de Liège, Belgium.
    Mawet, D.
    European Southern Observatory, Chile.
    Hanot, C.
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Pantin, E.
    CEA Saclay, France.
    Surdej, J.
    Université de Liège, Belgium.
    Habraken, S.
    Université de Liège, Belgium.
    A diamond AGPM coronagraph for VISIR2012In: Proceedings of SPIE: The International Society for Optical Engineering, 2012, p. 84468K-Conference paper (Refereed)
    Abstract [en]

    In recent years, phase mask coronagraphy has become increasingly efficient in imaging the close environment of stars, enabling the search for exoplanets and circumstellar disks. Coronagraphs are ideally suited instruments, characterized by high dynamic range imaging capabilities, while preserving a small inner working angle. The AGPM (Annular Groove Phase Mask, Mawet et al. 20051) consists of a vector vortex induced by a rotationally symmetric subwavelength grating. This technique constitutes an almost unique solution to the achromatization at longer wavelengths (mid-infrared). For this reason, we have specially conceived a mid-infrared AGPM coronagraph for the forthcoming upgrade of VISIR, the mid-IR imager and spectrograph on the VLT at ESO (Paranal), in collaboration with members of the VISIR consortium. The implementation phase of the VISIR Upgrade Project is foreseen for May-August 2012, and the AGPM installed will cover the 11-13.2 μm spectral range. In this paper, we present the entire fabrication process of our AGPM imprinted on a diamond substrate. Diamond is an ideal material for mid-infrared wavelengths owing to its high transparency, small dispersion, extremely low thermal expansion and outstanding mechanical and chemical properties. The design process has been performed with an algorithm based on the rigorous coupled wave analysis (RCWA), and the micro-fabrication has been carried out using nano-imprint lithography and reactive ion etching. A precise grating profile metrology has also been conducted using cleaving techniques. Finally, we show the deposit of fiducials (i.e. centering marks) with Aerosol Jet Printing (AJP). We conclude with the ultimate coronagraph expected performances.

  • 27. Delacroix, Christian
    et al.
    Absil, Olivier
    Carlomagno, Brunella
    Piron, Pierre
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mawet, Dimitri
    Habraken, Serge
    Surdej, Jean
    Development of a subwavelength grating vortex coronagraph of topological charge 4 (SGVC4)2014In: GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY V, 2014, Vol. 9147, article id 91478YConference paper (Refereed)
    Abstract [en]

    One possible solution to achieve high contrast direct imaging at a small inner working angle (IWA) is to use a vector vortex coronagraph (VVC), which provides a continuous helical phase ramp in the focal plane of the telescope with a phase singularity in its center. Such an optical vortex is characterized by its topological charge, i.e., the number of times the phase accumulates 2 pi radians along a closed path surrounding the singularity. Over the past few years, we have been developing a charge-2 VVC induced by rotationally symmetric subwavelength gratings (SGVC2), also known as the Annular Groove Phase Mask (AGPM). Since 2013, several SGVC2s (or AGPMs) were manufactured using synthetic diamond substrate, then validated on dedicated optical benches, and installed on 10-m class telescopes. Increasing the topological charge seems however mandatory for cancelling the light of bright stars which will be partially resolved by future Extremely Large Telescopes in the near-infrared. In this paper, we first detail our motivations for developing an SGVC4 (charge 4) dedicated to the near-infrared domain. The challenge lies in the design of the pattern which is unrealistic in the theoretically perfect case, due to state-of-the-art manufacturing limitations. Hence, we propose a new realistic design of SGVC4 with minimized discontinuities and optimized phase ramp, showing conclusive improvements over previous works in this field. A preliminary validation of our concept is given based on RCWA simulations, while full 3D finite-difference time-domain simulations (and eventually laboratory tests) will be required for a final validation.

  • 28.
    Delacroix, Christian
    et al.
    Hololab, Université de Liège.
    Absil, Olivier
    IAGL, Université de Liège.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mawet, Dimitri
    European Southern Observatory.
    Christiaens, Valentin
    IAGL, Université de Liège.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Boccaletti, Anthony
    LESIA-Observatoire de Paris.
    Baudoz, Pierre
    LESIA-Observatoire de Paris.
    Kuittinen, Markku
    Department of Physics and Mathematics, University of Eastern Finland.
    Vartiainen, Ismo
    Paul Scherrer Institut.
    Surdej, Jean
    IAGL, Université de Liège.
    Habraken, Serge
    IAGL, Université de Liège.
    Laboratory demonstration of a mid-infrared AGPM vector vortex coronagraph2013In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 553, p. A98-Article in journal (Refereed)
    Abstract [en]

    Context. Coronagraphy is a powerful technique to achieve high contrast imaging, hence to image faint companions around bright targets. Various concepts have been used in the visible and near-infrared regimes, while coronagraphic applications in the mid-infrared nowadays remain largely unexplored. Vector vortex phase masks based on concentric subwavelength gratings show great promise for such applications.

    Aims. We aim at producing and validating the first high-performance broadband focal plane phase mask coronagraphs for applications in the mid-infrared regime, and in particular the L band with a fractional bandwidth of  ~16% (3.5–4.1 μm).

    Methods. Based on rigorous coupled wave analysis, we designed an annular groove phase mask (AGPM) producing a vortex effect in the L band, and etched it onto a series of diamond substrates. The grating parameters were measured by means of scanning electron microscopy. The resulting components were then tested on a mid-infrared coronagraphic test bench.

    Results. A broadband raw null depth of 2 × 10-3 was obtained for our best L-band AGPM after only a few iterations between design and manufacturing. This corresponds to a raw contrast of about 6 × 10-5 (10.5 mag) at 2λ/D. This result is fully in line with our projections based on rigorous coupled wave analysis modelling, using the measured grating parameters. The sensitivity to tilt and focus has also been evaluated.

    Conclusions. After years of technological developments, mid-infrared vector vortex coronagraphs have finally become a reality and live up to our expectations. Based on their measured performance, our L-band AGPMs are now ready to open a new parameter space in exoplanet imaging at major ground-based observatories.

  • 29.
    Delacroix, Christian
    et al.
    Hololab, Université de Liège, Belgien.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mawet, Dimitri
    European Southern Observatory (ESO), Santiago, Chile.
    Absil, Olivier
    IAGL, Université de Liège, Belgien.
    Hanot, Charles
    IAGL, Université de Liège, Belgien.
    Surdej, Jean
    IAGL, Université de Liège, Belgien.
    Habraken, Serge
    Hololab, Université de Liège, Belgien.
    Design, manufacturing, and performance analysis of mid-infrared achromatic half-wave plates with diamond subwavelength gratings2012In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 51, no 24, p. 5897-5902Article in journal (Refereed)
    Abstract [en]

    In this paper, we present a solution for creating robust monolithic achromatic half-wave plates (HWPs) for the infrared, based on the form birefringence of subwavelength gratings (SWGs) made out of diamond. We use the rigorous coupled wave analysis to design the gratings. Our analysis shows that diamond, besides its outstanding physical and mechanical properties, is a suitable substrate to manufacture mid-infrared HWPs, thanks to its high refractive index, which allows etching SWGs with lower aspect ratio. Based on our optimized design, we manufactured a diamond HWP for the 11-13.2 mu m region, with an estimated mean retardance similar to 3.143 +/- 0.061 rad ( 180.08 +/- 3.51 degrees). In addition, an antireflective grating was etched on the backside of the wave plate, allowing a total transmittance between 89% and 95% over the band.

  • 30.
    Delacroix, Christian
    et al.
    Université de Liège, Belgium.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Mawet, Dimitri
    European Southern Observatory, Chile.
    Lenaerts, Cedric
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Absil, Olivier
    Université de Liège, Belgium.
    Hanot, Charles
    Université de Liège, Belgium.
    Surdej, Jean
    Université de Liège, Belgium.
    First manufactured diamond AGPM vector vortex for the L- and N- bands: metrology and expected performances2010Conference paper (Refereed)
  • 31. Delacroix, Christian
    et al.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Piron, Pierre
    Ruane, Garreth
    Huby, Elsa
    Carlomagno, Brunella
    Jolivet, Aïssa
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Absil, Olivier
    Mawet, Dimitri
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Surdej, Jean
    Habraken, Serge
    A family of subwavelength grating vortexcoronagraphs (SGVCs) with higher topological charge2015In: Techniques and Instrumentation for Detection of Exoplanets VII, 2015, Vol. 9605Conference paper (Refereed)
    Abstract [en]

    The subwavelength grating vortex coronagraph (SGVC) is a focal-planespiral-like phase mask whose key benefit is to allow high contrast imaging atsmall angles. Directly etched onto a CVD diamond substrate, it is well suitedto perform in the mid-infrared domain. It provides a continuous helicalphase ramp with a dark singularity in its center, and is characterized by itsnumber of phase revolutions, called the topological charge. Over the pasttwo years, we have manufactured several charge-2 SGVCs (a.k.a. annulargroove phase masks) and successfully demonstrated their performanceson 10-m class telescopes (LBT, VLT/NaCo, VLT/VISIR). To prevent stellarleakage on future 30-m class telescopes (E-ELT, TMT, GMT), a broaderoff-axis extinction is required, which can be achieved by increasing thetopological charge. We have recently proposed an original design for acharge-4 SGVC allowing less starlight to leak through the coronagraph, atthe cost of a degraded inner working angle. In this talk, we report on ourlatest development of higher charge SGVCs. From 3D rigorous numericalsimulations using a finite-difference time-domain (FDTD) algorithm, weConference 9605: Techniques and Instrumentationfor Detection of Exoplanets VIIR eturn to Contents +1 360 676 3290 · help@spie.org 647have derived a family of coronagraphs with higher topological charge(SGVC4/6/8). Our new optimization method addresses the principallimitation of such space-variant polarization state manipulation, i.e., theinconvenient discontinuities in the discrete grating pattern. The resultinggratings offer improved precision to the phase modulation compared toprevious designs. Finally, we present our preliminary manufacturing andmetrology results for infrared components down to the K-band.

  • 32.
    Delacroix, Christian
    et al.
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Absil, Olivier
    Université de Liège, Belgium.
    Hanot, Charles
    Université de Liège, Belgium.
    Surdej, Jean
    Université de Liège, Belgium.
    Mawet, Dimitri
    European Southern Observatory, Chile.
    Development of diamond AGPM coronagraphs for VISIR and NACO2012Conference paper (Refereed)
  • 33.
    Delacroix, Christian
    et al.
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Diamond subwavelength gratings for mid-infrared diamond AGPM coronagraph: manufacturing assessment2010Conference paper (Refereed)
  • 34.
    Delacroix, Christian
    et al.
    Liège University, Hololab Group.
    Habraken, Serge
    Liège University, Hololab Group.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Diamond subwavelength gratings for mid-infrared diamond AGPM coronagraph: manufacturing assessment2010In: EOSAM 2010, Paris, 2010Conference paper (Refereed)
    Abstract [en]

    We present the manufacturing and measurement results obtained with a mid-infrared (L- band ~ 3.8 μm) diamond Annular Groove Phase Mask (AGPM) coronagraph (Mawet et al 20051), using subwavelength gratings and diamond-optimized micro-fabrication techniques such as Nano-Imprint Lithography and Reactive Ion Etching.

     

  • 35.
    Enlund, Johannes
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. Avdelningen för fasta tillståndets elektronik.
    Isberg, Jan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. elektricitetslära och åskforskning.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. materialvetenskap.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Materials Science. materialvetenskap.
    Olsson, Jörgen
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electronics. fasta tillståndets elektronik.
    Twitchen, Daniel J.
    Element Six, UK.
    Anisotropic dry etching of boron doped single crystal CVD diamond2005In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 43, no 9, p. 1839-1842Article in journal (Refereed)
    Abstract [en]

    Semiconducting boron doped single-crystal CVD diamond has been patterned using aluminum masks and an inductively coupled plasma (ICP) etch system. For comparison insulating HPHT diamond samples were also patterned using the same process. Diamond etch rates above 200 nm/min were obtained with an O2/Ar discharge for a gas pressure of 2.5 mTorr using 600 W RF power. We have accomplished the fabrication of structures with a minimum feature size of 1 μm with vertical sidewalls in both CVD and HPHT diamond. The ICP etching produced smooth surfaces with a typical root-mean-square surface roughness of 3 nm. The dependence of etch rate on bias voltage was somewhat different for the two types of diamond. However, for all samples both the etch rate and anisotropy were found to improve with increasing bias voltage.

  • 36.
    Fagerqvist, Therese
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Näsström, Thomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ihse, Elisabet
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Lindström, Veronica
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Sahlin, Charlotte
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Fangmark Tucker, Stina M
    BioArctic Neuroscience AB.
    Kasaryan, Alex
    BioArctic Neuroscience AB.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Schell, Heinrich
    Department of Neurodegeneration, Hertie Institute for Clinical Brain Research and German Center for Neurodegenerative Diseases, Tübingen .
    Outeiro, Tiago. F
    Cell and Molecular Neuroscience Unit, Instituto de Medicina Molecular, Lisboa. Instituto de Fisiologia, Faculdade de Medicina da Universidade de Lisboa, Lisboa. Department of NeuroDegeneration and Restaurative Research, Universitätsmedizin Göttingen, Göttingen.
    Kahle, Philipp J
    Department of Neurodegeneration, Hertie Institute for Clinical Brain Research and German Center for Neurodegenerative Diseases, Tübingen .
    Lannfelt, Lars
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Ingelsson, Martin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Bergström, Joakim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Public Health and Caring Sciences, Geriatrics.
    Off-pathway alpha-synuclein oligomers seem to alter alpha-synuclein turnover in a cell model but lack seeding capability in vivo2013In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 20, no 4, p. 233-244Article in journal (Refereed)
    Abstract [en]

    Aggregated α-synuclein is the major component of Lewy bodies, protein inclusions observed in the brain in neurodegenerative disorders such as Parkinson’s disease and dementia with Lewy bodies. Experimental evidence indicates that α-synuclein potentially can be transferred between cells and act as a seed to accelerate the aggregation process. Here, we investigated in vitro and in vivo seeding effects of α-synuclein oligomers induced by the reactive aldehyde 4-oxo-2-nonenal (ONE). As measured by a Thioflavin-T based fibrillization assay, there was an earlier onset of aggregation when α-synuclein oligomers were added to monomeric α-synuclein. In contrast, exogenously added α-synuclein oligomers did not induce aggregation in a cell model. However, cells overexpressing α-synuclein that were treated with the oligomers displayed reduced α-synuclein levels, indicating that internalized oligomers either decreased the expression or accelerated the degradation of transfected α-synuclein. Also in vivo there were no clear seeding effects, as intracerebral injections of α-synuclein oligomers into the neocortex of α-synuclein transgenic mice did not induce formation of Proteinase K resistant α-synuclein pathology. Taken together, we could observe a seeding effect of the ONE-induced α-synuclein oligomers in a fibrillization assay, but neither in a cell nor in a mouse model.

  • 37.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Delacroix, Christian
    Université de Liège, Belgium.
    Mawet, Dimitri
    European Southern Observatory, Chile.
    Absil, Olivier
    Université de Liège, Belgium.
    Hanot, Charles
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Surdej, Jean
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Etching High Aspect Ratio Optical Gratings in Diamond2012Conference paper (Refereed)
  • 38.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Delacroix, Christian
    Université de Liège, Belgium.
    Mawet, Dimitri
    European Southern Observatory, Chile.
    Absil, Olivier
    Université de Liège, Belgium.
    Hanot, Charles
    Université de Liège, Belgium.
    Habraken, Serge
    Université de Liège, Belgium.
    Surdej, Jean
    Université de Liège, Belgium.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Fabricating an annular groove phase mask in diamond2012Conference paper (Refereed)
  • 39.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Jorge, Eleonora de Oliveira
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Inorganic Chemistry.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Fabrication of boron doped diamond microband electrodes for electrochemical detection in a microfluidic channel2011In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 20, no 8, p. 1121-1124Article in journal (Refereed)
    Abstract [en]

    The manufacturing and electrochemical characterisation of an array of 20 boron doped nanocrystalline diamond (BNCD) microband electrodes for use in a poly(dimethylsiloxane) (PDMS) based microfluidic system are described. The electrodes were fabricated by plasma etching of a silicon oxide- and BNCD thin film coated silicon wafer and the resulting surface structured silicon wafer was subsequently bonded to the PDMS so that the BNCD microband electrodes were located within the PDMS microchannel. The electrochemical performance of the BNCD electrodes was studied and the electrodes were found to exhibit significantly better stability than previously employed gold microband arrays.

  • 40.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    High aspect ratio optical gratings in diamond2013In: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 34, p. 19-24Article in journal (Refereed)
    Abstract [en]

    In this paper we describe a process for fabricating high aspect ratio gratings in single- or polycrystalline diamond with the high precision required by micro-optics. Nanoimprint lithography with a soft stamp and several layers of hard masks allowed for rapid and accurate replication of patterns written by e-beam or laser into thick Al masks on diamond substrates as large as 2 cm in diameter. Vertical sidewalls in the mask were crucial for avoiding microvilli formation during diamond plasma etching and were achieved by etching and oxidizing the Al mask in cycles. Circularly symmetric half-wave plates for wavelength bands around 4 and 11 mu m were fabricated with deep circular gratings on one side and antireflective gratings on the other.

  • 41.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Inclined surfaces in diamond: broadband antireflective structures and coupling light through waveguides2013In: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 21, no 3, p. 2693-2700Article in journal (Refereed)
    Abstract [en]

     Control of the sidewall angle of diamond microstructures was achieved by varying the gas mixture, bias power and mask shape during inductively coupled plasma etching. Different etch mechanisms were responsible for the angle of the lower and upper part of the sidewall formed during diamond etching. These angles could to some extent be controlled separately. The developed etch process was used to fabricate wideband antireflective structures with an average transmission of 96.4% for wavelengths between 10 and 50 mu m. Smooth facetted edges for coupling light through waveguides from above were also demonstrated. 

  • 42.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Malmström, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Diamond grating waveplates2016In: Optical Materials Express, ISSN 2159-3930, E-ISSN 2159-3930, Vol. 6, no 6, p. 2024-2030Article in journal (Refereed)
    Abstract [en]

    Two designs of diamond quarter-wave plates for CO2 lasers, based on the birefringence of sub-wavelength gratings, were manufactured and tested. In one design the grating was etched on the surface of a 300 µm thick polycrystalline diamond substrate. The other consisted of a diamond grating hanging freely in air, suspended at the edges from a silicon frame. The free-hanging design, while more fragile, had several advantages both in terms of fabrication and performance such as a larger grating period, higher transmission, and no need for an antireflective treatment of the backside.

  • 43.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Cassie-Wenzel and Wenzel-Cassie transitions on immersed superhydrophobic surfaces under hydrostatic pressure2011In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 7, no 1, p. 104-109Article in journal (Refereed)
    Abstract [en]

    For incorporating superhydrophobic surfaces in microfluidic systems, it is important to understand the ability of the superhydrophobic state to withstand hydraulic pressure. In this paper we describe experiments to probe the collapse transition on superhydrophobic surfaces completely covered by water, where the air film formed on the surface is closed. Polyethylene foils nanoimprinted with micrometre sized pillars in different geometries and densities are used as the model superhydrophobic surfaces. The pressure required for the transition from Cassie to Wenzel state is measured for all surfaces and also compared to analytical and numerical models. We find that the closed film of trapped air helps stabilise the Cassie state at low pillar densities and that the effect of a small change in pillar sidewall angle can drastically change the collapse behaviour. Finally, the reverse transition, from Wenzel to Cassie state, is observed on densely pillared surfaces at low water pressure.

  • 44.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Wettability control and superhydrophobicity on diamond2010Conference paper (Refereed)
  • 45.
    Forsberg, Pontus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Vargas, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Delacroix, Christian
    Absil, Olivier
    Carlomagno, Brunella
    Mawet, Dimitri
    Habraken, Serge
    Surdej, Jean
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Realizing the diamond annular groove phase masks for the mid infrared region - five years of successful process development of diamond plasma etching2014Conference paper (Refereed)
  • 46.
    Fromell, Karin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Clinical Immunology.
    Forsberg, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Larsson, Karin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Baltzer, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Designed protein binders in combination with nanocrystalline diamond for use in high-sensitivity biosensors2012In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 404, no 6-7, p. 1643-1651Article in journal (Refereed)
    Abstract [en]

    A platform for diagnostic applications showing signal-to-noise ratios that by far surpass those of traditional bioanalytical test formats has been developed. It combines the properties of modified nanocrystalline diamond (NCD) surfaces and those of polyethylene oxide and polypropylene oxide based block copolymers for surface passivation and binder conjugation with a new class of synthetic binders for proteins. The NCD surfaces were fluorine-, hydrogen-, or oxygen-terminated prior to further biofunctionalization and the surface composition was characterized by X-ray photoelectron spectroscopy. In a proof of principle demonstration targeting the C-reactive protein, an ELISA carried out using an F-terminated diamond surface showed a signal-to-noise ratio of 3,900 which compares well to the signal-to-noise of 89 obtained in an antibody-based ELISA on a polystyrene microtiter plate, a standard test format used in most life science laboratories today. The increase in signal-to-noise ratio is to a large extent the result of extremely efficient passivation of the diamond surface. The results suggest that significant improvements can be obtained in standardized test formats using new materials in combination with new types of chemical coatings and receptor molecules.

  • 47.
    Gonzalez, Carlos Alberto Gomez
    et al.
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.
    Wertz, Olivier
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.
    Absil, Olivier
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.
    Christiaens, Valentin
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.; Univ Chile, Dept Astron, Santiago, Chile.; Millennium Nucleus Protoplanetary Disks, Santiago, Chile.
    Defrère, Denis
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.
    Mawet, Dimitri
    CALTECH, Dept Astron, Pasadena, CA 91125 USA.; Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
    Milli, Julien
    European Southern Observ, Santiago, Chile.
    Absil, Pierre-Antoine
    Catholic Univ Louvain, Dept Math Engn, B-1348 Louvain La Neuve, Belgium.
    Van Droogenbroeck, Marc
    Univ Liege, Inst Montefiore, B-4000 Liege, Belgium.
    Cantalloube, Faustine
    CNRS, IPAG, F-38000 Grenoble, France.; Off Natl Etud & Rech Aerosp, Opt Dept, BP 72, F-92322 Chatillon, France.
    Hinz, Philip
    Univ Arizona, Dept Astron, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA.
    Skemer, Andrew
    Univ Calif Santa Cruz, 1156 High St, Santa Cruz, CA 95064 USA.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Surdej, Jean
    Univ Liege, Space Sci Technol & Astrophys Res STAR Inst, Allee Six Aout 19c, B-4000 Liege, Belgium.
    VIP: Vortex Image Processing Package for High-contrast Direct Imaging2017In: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 154, no 1, article id 7Article in journal (Refereed)
    Abstract [en]

    We present the Vortex Image Processing (VIP) library, a python package dedicated to astronomical high-contrast imaging. Our package relies on the extensive python stack of scientific libraries and aims to provide a flexible framework for high-contrast data and image processing. In this paper, we describe the capabilities of VIP related to processing image sequences acquired using the angular differential imaging (ADI) observing technique. VIP implements functionalities for building high-contrast data processing pipelines, encompassing pre- and post-processing algorithms, potential source. position and flux estimation, and sensitivity curve. generation. Among the reference point-spread. function subtraction techniques for ADI post-processing, VIP includes several flavors of principal component analysis (PCA) based algorithms, such as annular PCA and incremental PCA algorithms capable of processing big datacubes (of several gigabytes) on a computer with limited memory. Also, we present a novel ADI algorithm based on non-negative matrix factorization, which comes from the same family of low-rank matrix approximations as PCA and provides fairly similar results. We showcase the ADI capabilities of the VIP library using a deep sequence on HR 8799 taken with the LBTI/LMIRCam and its recently commissioned L-band vortex coronagraph. Using VIP, we investigated the presence of additional companions around HR 8799 and did not find any significant additional point source beyond the four known planets. VIP is available at http://github. com/vortex-exoplanet/VIP and is accompanied with Jupyter notebook tutorials illustrating the main functionalities of the library.

  • 48.
    Haas, Julian
    et al.
    Ulm University, Germany.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Piron, Pierre
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mizaikoff, Boris
    Ulm University, Germany.
    Infrared Spectroscopy based on Broadly Tunable Quantum Cascade Lasers and Polycrystalline Diamond Waveguide2018In: Analyst, ISSN 0003-2654, Vol. 143, no 21, p. 5112-5119Article in journal (Refereed)
  • 49.
    Haas, Julian
    et al.
    Ulm University, Germany.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Piron, Pierre
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Nikolajeff, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Mizaikoff, Boris
    Ulm University, Germany.
    Polycrystalline diamond thin-film waveguides for mid-infrared evanescent field sensors2018In: ACS Omega, ISSN 2470-1343, Vol. 3, no 6, p. 6190-6198Article in journal (Refereed)
    Abstract [en]

    Photonic design and optimization of thin-film polycrystalline diamond waveguides are shown, serving as advanced evanescent field transducers in the mid-infrared fingerprint regime (2000-909 cm(-1); 5-11 mu m). Design constraints inherent to optical/system considerations and the material were implemented in a finite element method (FEM)-based simulation method that allowed three-dimensional modeling of the overall structure. Thus, lateral mode confinement, attenuation in the direction of radiation propagation, and physical resilience were evaluated. In a final step, the designed structures were fabricated, and their utility in combination with a broadly tunable external cavity quantum cascade laser for chemical sensing of a liquid phase analyte was demonstrated.

  • 50.
    Hamberg, Mathias
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Vargas Catalan, Ernesto
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Karlsson, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Dancila, Dragos
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA. Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Rydberg, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Ögren, Jim
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Jacewicz, Marek
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, FREIA. Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, High Energy Physics.
    Kuittinen, M.
    Institute of Photonics, University of Eastern Finland, Finland.
    Vartiainen, I.
    Institute of Photonics, University of Eastern Finland, Finland.
    Dielectric Laser Acceleration Setup Design, Grating Manufacturing and Investigations Into Laser Induced RF Cavity Breakdowns2017In: Proceedings of FEL2017, Santa Fe, NM, USA, 2017Conference paper (Refereed)
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