Insertable pulse cleaning module with a saturable absorber pair and a compensating amplifier for high-intensity ultrashort-pulse lasers

可飽和吸収体対とエネルギー補償増幅器を備えたパルス時間波形向上装置

余語 覚文; 近藤 公伯; 森 道昭; 桐山 博光; 小倉 浩一; 下村 拓也; 井上 典洋*; 福田 祐仁; 榊 泰直; 神野 智史   ; 金崎 真聡; Bolton, P.

Yogo, Akifumi; Kondo, Kiminori; Mori, Michiaki; Kiriyama, Hiromitsu; Ogura, Koichi; Shimomura, Takuya; Inoue, Norihiro*; Fukuda, Yuji; Sakaki, Hironao; Jinno, Satoshi; Kanasaki, Masato; Bolton, P.

We demonstrate the performance of an efficient insertable pulsecleaning module that uses a saturable absorber pair with a compensatingmulti-pass amplifier. The module is implemented with a conventional CPATi:sapphire laser system. It suppresses the amplified spontaneous emission (ASE) level of the pulse pedestal by about three orders of magnitude whilepreserving the output pulse energy and repetition-rate of the overall lasersystem. The effectiveness of the cleaning module is confirmed in laserdrivenproton acceleration experiments. At the 10 W/cm pedestal level, the surface structure and electrical resistivity of an insulator target (100 nmsilicon nitride) are preserved prior to the arrival of the intense ultrashortpulse.