激光双谱线功率的不一致性与拍波干涉仪对准精度的关系

Dependence of the Aiming Accuracy of a Beat wave Interferometer on Laser Dual line Output Power Equilibrium

双谱线功率一致性是拍波干涉测长方案对激光光源提出的特殊要求。本文从拍波干涉仪对准方法的实际出发，在分析双谱线拍波干涉仪输出信号的基础上，研究了双谱线功率不一致与拍波干涉仪对准精度的关系，提出了基本对准盲区和盲区扩大量的新概念，建立了描述盲区扩大量与双谱线相对功率差之间关系的解析表达式。为设计拍波干涉仪的激光稳定环路和提高拍波干涉仪的对准精度提供了理论分析工具。

Output power equalization of laser dual spectrum lines is a special requirement which is put on its laser source by two wavelength beat wave absolute distance interferometry.On the basis of analyzing the output signal of a two wavelength beat wave absolute distance interferometer,this paper proceeds from the realities of the aiming method of the beat wave interferometer,conducts an analytical investigations on the dependence of the aiming accuracy of the beat wave interferometer on laser dual line output power equilibrium,propose two new concepts-a basic aim blind area and a blind area expansion,and establishes an analytical expression between the blind area expanssion and the relative power difference of laser dual lines.The result provides an analytical tool for designing the laser stabilized servo loop of the instrument and improving its aiming accuracy.