[19p-E204-1~12] 3.13 Semiconductor optical devices

[19p-E204-12] Fast optical response of GaAs in the NIR region to femtosecond X-ray pulse excitation

〇(M1)Keisuke Kondo^1,2, Wataru Nishimura^1,2, Motohiro Suzuki³, Nobuhiro Yasuda³, Yoshimitsu Fukuyama³, Yuya Kubota^2,3, Tadashi Togashi^2,3, Takayuki Hasegawa¹, Yoshihito Tanaka^1,2 (1.Univ. of Hyogo, 2.RIKEN/SPring-8, 3.JASRI)

Keywords:XFEL, semiconductor

Fast optical response around the bandgap was observed in order to investigate the band structure dynamics of a semiconductor irradiated by X-ray pulses. Transient transmission spectra of a 10 micron thick-GaAs were obtained by a pump probe method, where X-ray free electron laser pulses were used for pump, and broadband near infrared pulses were used for probe. The changes in the spectral profiles were shown in the time scale of picoseconds after the X-ray pulse excitation. We discuss the relationship between the results, and the bandgap shift and the population change.