基于周期极化LiTaO3晶体的高增益简并啁啾脉冲参量放大

根据准相位匹配理论计算了周期极化LiTaO₃(PPLT)晶体中0类准相位匹配过程(e+e→e)的增益曲线.在此基础上，使用数百μJ的低抽运能量获得了～10⁶的增益和～10.3%的转换效率，实现了中心波长位于1064nm的基于简并光学啁啾脉冲参量放大(OPCPA)技术的高增益放大，为产生超短超强激光脉冲提供了新的技术手段.实验结果与理论预期基本符合.     

基于周期极化LiTaO3晶体的高增益简并啁啾脉冲参量放大

根据准相位匹配理论计算了周期极化LiTaO3(PPLT)体中0类准相位匹配过程(e+e→e)的增益曲线.在此基础上,使用数百μJ的低抽运能量获得了～106的增益和-10.3%的转换效率,实现了中心波长位于1064nm的基于简并光学啁啾脉冲参量放大(OPCPA)技术的高增益放大,为产生超短超强激光脉冲提供了新的技术手段.实验结果与理论预期基本符合.     

Investigation of near-collinear degenerated quasi-phase matching optical parametric amplification using PPKTP crystal

The gain properties of near-collinear degenerated phase-matched optical parametric amplification (OPA) using PPKTP crystal are investigated theoretically. The results indicate that the type-0 phase matching of PPKTP has larger accepted angle and better gain spectrum by tuning crystal temperature or rotating crystal angle.     

High-power output from a compact OPCPA laser system

With a tabletop hybrid Nd:YAG-Nd:glass laser as pump source, a compact optical parametric chirpedpulse amplification(OPCPA)laser system with a peak output power of 16.7 TW and a pulse duration of120 fs has been demonstrated.Chirped pulses are amplified from 50 pJ to more than 3.1 J with an energygain of above 6×10~(10)by three LBO optical parametric amplifiers with a pump energy of 12.4 J at 532nm.After compression, a final output of 2.0-J/120-fs pulse is obtained. To the best of our knowledge,itis the highest peak output power from an OPCPA laser so far.In addition, a practical design of 1-PWlaser system based on the technique of OPCPA is also proposed.     

不透明高密度聚乙烯覆盖下硝酸钠的拉曼光谱研究

空间偏移拉曼光谱技术(SORS)作为一种新型拉曼光谱技术,其光谱收集系统与激光入射点在空间位置上有一定的偏移距离~([1]),具有很好的抑制表层成分拉曼光谱及荧光光谱的能力,能够实现不/半透明材料覆盖下内部成分拉曼光谱的无损、快速检测~([2-4])。研究团队基于建立空间偏移拉曼光谱探测系统,已成功实现了不透明介质覆盖下隐藏成分的探测,针对偏移距离对于空间偏移拉曼光谱探测信号强度的影响进行了实验研究及分析。     

Dispersion Analysis and Compensation of Collinear Optical Parametric Chirped Pulse Amplification Systems

In an optical parametric chirped pulse amplification （OPCPA） laser system, residual phase dispersion should be compensated as much as possible to shorten the amplified pulses and improve the pulse contrast ratio. Expressions of orders of the induced phases in collinear optical parametric amplification （OPA） processes are presented at the central signal wavelength to depict a c/ear physics picture and to simplify the design of phase compensation. As examples, we simulate two OPCPA systems to compensate for the phases up to the partial fourth-order terms, and obtain flat phase spectra of 200-nm bandwidth at 1064nm and 90-nm at 800nm.