A 4 mJ femtosecond Ti：sapphire regenerative amplifier at 1 kHz repetition rate

Abstract

To meet the application requirements for high energy kHz repetition rate femtosecond laser, a high-efficiency femtosecond Ti:sapphire linear regenerative amplifier is designed. By optimizing the parameters of the cavity, 5.8 mJ chirped pulses at 800 nm are obtained, under pump energy of 20 mJ with wavelength of 527 nm at 1 kHz repetition rate, corresponding to a slope efficiency of 30.7%. By compensating for the dispersion, 4 mJ laser pulses at 800 nm with pulse duration of 45.7 fs are achieved. The energy fluctuation is 0.18% (RMS) in 5 h.

High contrast amplification at 1053??nm limited by pulse stretching-compressing process

“…These techniques have been proven to be effective for improving pulse contrast, but high energy loss causes by cleaning process could not be compensated, which seriously decreases the peak power of the pulse. Therefore, many temporal precleaning techniques were used to generate high-contrast seed pulses, such as saturable absorbers (SAs) [9] , cross polarized wave generation (XPW) [10] , and short pulse optical parametric amplification (OPA) [11,12] . Usually, by highcontrast high-energy seed injection, the ASE could be suppressed efficiently in the amplification process.…”