气动激光窗口的光束传输特性

本文分析和实验研究了HAW型气动激光窗口所形成的小孔光阑效应和类透镜效应对光束传输的影响,阐明了在高功率气体激光器中使用气动激光窗口的优越性。     

砷化镓晶体在连续CO_2激光作用下的三阶非线性系数

用千瓦级连续CO_2激光作光源,得到复合型砷化镓材料的三阶非线性系数为8.3×10~(-7)esu,同时根据这种材料的杂质能级对其三阶非线性系数进行计算,所得结果与实验相符。     

脉冲激光推进轻型飞行器的特点分析

采用微分方程数值解法计算地基脉冲激光推进轻型飞行器的运动方程，分析了大气呼吸模式、烧蚀模式以及两种模式相结合方式下飞行器的飞行特点。计算分析发现：空气呼吸模式推进飞行器的最大速度有限；烧蚀模式可以使飞行器产生很高的速度，提高冲量耦合系数和比冲，有利于提高飞行器的最高速度；两种模式相结合的推进方式提高了有效载荷比，但能源利用效率比烧蚀模式要低。为轻型飞行器激光推进的优化提供了参考。     

An Efficient Pulsed CH3OH Terahertz Laser Pumped by a TEA CO2 Laser

An efficient pulsed CH3OH terahertz （THz） laser pumped by a TEA CO2 laser is investigated experimentally. To improve photon conversion efficiency and THz laser energy, two cavity configurations of the TEA CO2 laser, which is external and semi-external, are evaluated. The pump intensities are about 4.7 MW/cm2 and 1.2 MW/cm2, respectively. Higher pump intensity and more stable single lines are obtained in the external cavity. For the 3.8 J pump energy of the 9P（16） transition in the external cavity, the maximum terahertz output energy with 570.5 μm wavelength at 160 Pa is 431 μJ. With a 6 J energy pulse in terms of a semi-external cavity, a 353 μJ terahertz emission （570.5 μm） is produced. The corresponding photon conversion efficiencies are 1.36% and 0.705%, increasing by a factor of about 2.