摘要
文章报导了基于大基模体积的高能量飞秒钛宝石激光再生放大器的设计与实验研究,在重复频率10 Hz、抽运能量60 mJ的激励下,得到了单脉冲能量17.4 mJ的种子脉冲放大结果,压缩后的脉冲宽度为40.6 fs,能量为13.9 mJ.借助于此大基模体积再生腔,仅增加一级多通放大,实现了峰值功率达1.9 TW飞秒激光脉冲输出.结果表明,大模体积再生放大不仅降低了后续放大对抽运能量的要求,也可以单独压缩实现再生腔直接输出10 mJ量级的飞秒激光脉冲,是大能量高峰值功率飞秒激光系统的优质前端.
With advent of chirped-pulse amplification, the peak power of femtosecond laser pulse was reached to petawatt （PW） or hundreds of terawatt （TW）. Many progresses of high-field physics and ultrafast dynamics in matter are achieved using TW or PW laser. Pre-amplifier is an exponential growth amplifier which is also a bridge between oscillator and power amplifier. The best choice of pre-amplifier is amplification in regenerative cavity, due to its high stability and beam quality. The quality of pre-amplified laser pulse is significant to efficiency and beam quality of the successive power amplifier. High energy pre-amplifier with high beam quality will reduce the requirement of pump laser in final power amplifier. But typical regenerative amplifier only support low output energy of few millijoule. Higher energy from only one regenerative amplifier is crucial to whole laser system.#br#High energy regenerative amplifier can be achieved by increasing the size of TEM00 in cavity. A new femtosecond Ti：sapphire regenerative amplifier with large mode size was demonstrated in this letter. The regenerative cavity is designed as stable linear resonator in which end mirrors are planar, the diameter of beam waist in Ti：sapphire crystal is larger than 2 mm, which can support high energy pulse amplified in cavity. By matching the focal spot of pump laser with the size of mode and optimization of cavity, the output laser energy up to 17.4 mJ was achieved under the pump energy of 60 mJ at repetition rate of 10 Hz, which corresponds to the efficiency of 29%. The amplified laser pulse from regenerative amplifier was compressed in a grating-pair compressor. By carefully alignment of incident angle and distance between the two gratings of compressor, the shortest pulses duration of 40.6 fs and energy of 13.9 mJ are obtained, which is a little bit longer than Fourier-transform limit based on spectrum of laser. The dispersion in the CPA laser system was also analyzed, after optimization of compressor, there are still high orde
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第10期152-158,共7页
Acta Physica Sinica
基金
国家重大科学仪器设备开发专项基金(批准号:2012YQ12004701)
国家重点基础研究发展计划(批准号:2013CB922401)
国家自然科学基金(批准号:11474002,11674386)资助的课题~~
关键词
飞秒激光
啁啾脉冲放大
再生放大器
太瓦
femtosecond laser, chirped-pulse amplification, regenerative amplifier, terawatt
