用于激光推进的高功率激光器的选择

 从激光推进的要求出发，阐述了用于激光推进的高功率激光器的选择原则，即激光器必须满足：（1）高的平均功率和峰值功率；（2）高的单脉冲能量；（3）高的重复频率；（4）优良的大气传输特性。主要分析了目前YAG固体激光器、自由电子激光器和TEA脉冲CO₂激光器的特点，通过上述4个方面性能的比较，认为在目前水平下，TEA脉冲CO₂激光器是进行激光推进的首选强激光源，其优点表现在：功率可达10kW量级，单脉冲能量可达0.5~1kJ，重复频率为20~40Hz；激光波长处于大气传输窗口，对大气变化不敏感；工作物质快速流动，不存在热透镜效应和破坏阈值；相关光学元件易于制造；光束质量较好；运行成本低。

Choosing high-power laser in laser propulsion technology

Based on the requirement of laser propelling, this paper illuminates in how to choose the high power laser.The requirements on the laser are: (1) high average power and peak power;(2) high single-pulse energy;(3) high repetition frequency;(4) excellent transmitting property in atmosphere. The paper mainly analyzes the characteristics of YAG laser, free electron laser and TEA CO_2 laser, compares their average power, peak power, high single-pulse energy, and transmitting property in atmosphere. The result shows nowadays, TEA CO_2 laser is the most appropriate one at present to be used as the high power source in the field.It's power can reach 10kW level, single pulse energy can reach 0.5～1kJ, repetitive frequency is 20～40Hz, the laser wavelength lies in the atmospheric window, and it isn't sensitive to the atmospheric change. The laser work media flows fast, and it has no the thermal lens effect and damage threshold. The optical components are easy to be machined, the beam quality is better than other laser, and the operational cost is low.