Trends in ultrashort and ultrahigh power laser pulses based on optical parametric chirped pulse amplification

Since the proof-of-principle demonstration of optical parametric amplification to efficiently amplify chirped laser pulses in 1992,optical parametric chirped pulse amplification(OPCPA)became the most promising method for the amplification of broadband optical pulses.In the meantime,we are witnessing an exciting progress in the development of powerful and ultrashort pulse laser systems that employ chirped pulse parametric amplifiers.The output power and pulse duration of these systems have ranged from a few gigawatts to hundreds of terawatts with a potential of tens of petawatts power level.Meanwhile,the output pulse duration based on optical parametric amplification has entered the range of fewoptical-cycle field.In this paper,we overview the basic principles,trends in development,and current state of the ultrashort and laser systems based on OPCPA,respectively.     

光纤飞秒激光五倍频产生206 nm深紫外激光

深紫外飞秒激光兼具深紫外激光单光子能量高和飞秒激光峰值功率高的优势,这使得深紫外飞秒激光在半导体晶圆检测和角分辨光电子能谱等领域被广泛应用,但是色散导致的群速度失配使得深紫外飞秒激光的输出变得十分困难,本文基于掺镱光纤飞秒激光器,实现了一种基于延迟线的深紫外飞秒激光脉冲产生方案.通过优化延迟线精确补偿时间走离,基于掺镱飞秒光纤激光五倍频获得了重复频率为1 MHz、中心波长为206 nm的深紫外飞秒激光输出,其平均功率102 mW,从近红外到深紫外的转换效率为4.25%.     

Hybrid femtosecond laser system based on a Yb:KGW regenerative amplifier for N_P polarization

We report a hybrid femtosecond laser system based on a femtosecond Yb-doped fiber laser and a Yb-doped potassium gadolinium tungstate(Yb:KGW) regenerative amplifier. To match the central wavelength of the seed source, a Yb:KGW crystal is used in the regenerative amplifier for N_p polarization. We study and optimize the dynamics of nonlinear amplification to alleviate the gain narrowing effect. With optimization, the system can output 270 fs pulses with 21 μJ pulse energy at a 60 kHz repetition rate.