激光偏振方向和强度变化对分光光强的影响

在双光路补偿强度调制型光电检测系统中，采用分光镜后透射光强和反射光强会随着激光光源偏振方向和强度的变化而变化，这严重破坏了强度补偿机理。详细推导了激光光源偏振方向变化时分光比的变化公式，举例说明了分光比随偏振角的变化情况，并给出了反射光强和透射光强的变化规律。重点讨论了当激光光源偏振方向和强度同时变化时分光比的变化规律。提出了采用偏振光源或偏振片的两种解决办法。

Influence of polarization direction and intensity of laser on splitting intensity

In the plotoelectric detecting system using double light path compensation technology, the transmitted intensity and reflected intensity from the splitter change with the polarization direction and the intensity of the laser, which influences the intensity compensation. On condition that the polarization direction varies alone, a formula about the ratio between the transmitted intensity and reflected intensity is derived, which are illuminated by a example, and the varying rules of the transmitted intensity and reflected intensity are analyzed. While both the polarization direction and the intensity vary at the same time, the rules of the transmitted intensity and reflected intensity varying are discussed. A solution to the influence is put forward.