Monochromatizing and focussing femtosecond high-order harmonic radiation with one optical element
2013 (English)In: Review of Scientific Instruments, ISSN 0034-6748, E-ISSN 1089-7623, Vol. 84, no 10, 103102- p.Article in journal (Refereed) Published
A novel approach for monochromatizing and focussing the Vacuum-Ultraviolet and soft x-ray radiation from high-order harmonic generation of a femtosecond optical laser with only one optical element is presented. We demonstrate that off-axis reflection zone plates applied as focussing monochromators allow for efficiently optimizing the trade-off between energy resolution and temporal dispersion of the femtosecond pulses. In the current experimental realization, we show how the temporal dispersion can be varied between 2 fs and 16 fs with a correlating variation of the energy resolution E/Delta E between 20 and 90 for an off-axis reflection zone plate optimized for harmonic 13 at 20.41 eV. We also show how the focal spot size varies correspondingly between 80 x 90 mu m(2) and 290 x 140 mu m(2) as determined with a computational fitting approach based on a 3D Gaussian model. The diffraction efficiency for the tested zone plates amounts to up to 10%. We furthermore evaluate the influence of pointing stability on the performance of the zone plates. Based on our results we propose an optimized realization of a dedicated beam line for femtosecond pulses from high-order harmonic generation with an off-axis reflection zone plate.
Place, publisher, year, edition, pages
2013. Vol. 84, no 10, 103102- p.
IdentifiersURN: urn:nbn:se:uu:diva-212421DOI: 10.1063/1.4822114ISI: 000326645300003OAI: oai:DiVA.org:uu-212421DiVA: diva2:677880