本文研究了非稳腔激光束发散度与腔的放大倍数的关系，并提出了非稳腔设计的原则。
In this article we discuss the relation between the laser beam divergence and the amplification factor in unstable cavities and the principles for the design of unstable resonators are given.
实验表明，经该方法准直后的光束发散角（会聚角）可达0.00007 度。
Experiments have verified that the divergence angle of the light after collimation is up to 0.000070.
激光雷达系统的作用距离由下列因素决定：脉冲能量、脉冲宽度、光束发散角、大气衰减、目标反射率和接收机灵敏度等。
The operating distance of a laser radar system is determined on pulse energy, pulse width, beam divergence angular, atmosphere attenuation, target reflection, receiver sensitivity and so on.
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