Leitner, T.; Sorokin, A.A.; Gaudin, J.; Kaser, H.; Kroth, U.; Tiedtke, K.; Richter, M.: Wernet, Ph.: Shot-to-shot and average absolute photon flux measurements of a femtosecond laser high-order harmonic photon source. New Journal of Physics 13 (2011), p. 093003/1-11
Open Accesn Version

The absolute flux of a femtosecond vacuum-ultraviolet (VUV) photon source based on the high-order harmonic generation of a femtosecond Ti:sapphire laser and monochromatized with a grating monochromator is determined both on a shot-to-shot basis and averaged over seconds by a calibrated gas monitor detector. The average flux is compared with the average flux as determined with a calibrated GaAsP semiconductor photodiode. We found that the photodiode is a reliable and easy-to-use tool for estimating the order of magnitude of the average photon flux but that, due to saturation losses, it underestimates the average flux by up to −15%.