Widely tunable high harmonic generation by truncated beams
Pei-Chi Huang1,2*, Hung-Wei Sun1, Ren-Ting Huang1, Ming-Chang Chen1
1Institute of Photonics Technologies, National Tsing Hua University, Hsinchu, Taiwan
2Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
* presenting author:Pei-Chi Huang, email:i9xas9966514@gmail.com
By simply controlling the size of an iris to truncate the driving fundamental, interestingly we are able to shift the central energy of high order harmonic generation to a higher photon energy. Especially in Ar, we demonstrated a very high flux and a wide energy tunability of harmonics from 35 eV to 65 eV, which is not observed before. Such a simple truncated scheme is unique and robust, producing a very bright photon flux at 60 eV, which is more than 30 times brighter than that regularly generated from Ne. This high flux light source represents an advance for ultrafast element-selective magneto-optic experiments, e.g. M-shell absorption edges of Co, Fe, Ni.

Keywords: high harmonic generation, extreme ultraviolet, ultrafast