Author Affiliations
Abstract
We experimentally investigate the high-order harmonic generation in argon gas cell driven by a multi-cycle broadband infrared laser pulse from a tunable optical-parametric-amplifier (OPA) source. The generation of high-order harmonic continuum with the cut-off photon energy up to 110 eV is observed by tuning the chirp of the 800-nm laser pulse which pumps OPA source. The generation of harmonic continuum is understood in terms of the two-hump structure of the OPA output spectrum and the optimal relative phase of the two humps. The demonstrated scheme is of importance for the generation of extreme ultraviolet (XUV) continuum at higher photon energy region.
020.2649 Strong field laser physics 190.2620 Harmonic generation and mixing 190.4410 Nonlinear optics, parametric processes Chinese Optics Letters
2014, 12(3): 030201
Author Affiliations
Abstract
State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
Two different pulse cleaning techniques for ultra-high contrast laser systems are comparably analysed in this work. The first pulse cleaning technique is based on noncollinear femtosecond optical-parametric amplification (NOPA) and second-harmonic generation (SHG) processes. The other is based on cross-polarized wave (XPW) generation. With a double chirped pulse amplifier (double-CPA) scheme, although temporal contrast enhancement in a high-intensity femtosecond Ti:sapphire chirped pulse amplification (CPA) laser system can be achieved based on both of the techniques, the two different pulse cleaning techniques still have their own advantages and are suitable for different contrast enhancement requirements of different laser systems.
pulse cleaning temporal contrast chirped pulse amplification High Power Laser Science and Engineering
2013, 1(2): 02000098
中国科学院上海光学精密机械研究所强场激光物理国家重点实验室, 上海 201800
描述了一套二次谐波型频率分辨光学快门(SHG-FROG)装置，用于单次测量红外长波长超快激光脉冲的脉宽和相位信息。针对在该波段宽带的高损伤阈值介质膜镀膜困难，且价格昂贵的问题，采用两个半圆形全反平面银镜来代替传统的半透半反镜进行分光。同时改进后的光路可以减少测量误差，结构更加紧凑且便于调节。采用该装置对基于钛宝石参量放大的红外超快脉冲进行测试，得到当中心波长为1.8 μm时，脉宽为66.9 fs，谱宽54.5 nm，谱相中的二阶群延时色散(GDD)为202.9 fs2。
超快光学 频率分辨光学快门 红外 超快激光
Author Affiliations
Abstract
State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
The influence on the level of amplified spontaneous emission (ASE) contrast resulting from the different seed pulse energies has been experimentally studied in a 10-TW-level femtosecond Ti:sapphire chirped pulse amplification laser. It is found that, with the seed pulse energy increasing, the ASE pedestal is suppressed more efficiently, and the ASE contrast is improved with a saturable tendency. The measurement of ~2×10-8 ASE contrast in the range of more than 50 ps before the main pulse is achieved in the laser.
对比度 自发辐射放大 飞秒啁啾脉冲放大激光器 320.0320 Ultrafast optics 140.0140 Lasers and laser optics Chinese Optics Letters
2010, 8(1): 123
