激光光斑形状及入射角对PSD位置输出影响的研究

位置敏感探测器（PSD）探测的是光斑能量的重心位置,通常利用半导体激光器作为PSD位置探测的光源。半导体激光器的光源存在衍射现象,入射角度的变化会引起光斑能量重心的变化,从而导致PSD输出特性的变化。本文通过计算得出圆光斑和＂十＂字形光斑的能量分布,光阑半径越小,光波长越长,衍射现象越明显,对PSD的输出影响越大。通过分析入射角变化对PSD输出特性的影响得出：入射光线在PSD敏感面垂直位置附近发生小角度变化时,重心的偏移会很微小,对PSD的输出特性影响较小。

Study on Effect of Laser Shape and Incident Angle on PSD Location

Position sensitive detectors（PSD） detect the gravity point of the light spot energy.Semiconductor lasers are usually used as the light source of PSD,and they may bring about the phenomenon of diffraction.Changes of the incident angle will lead to the changes of gravity point of the light spot energy,which eventually lead to the changes in output characteristics of PSD.By calculating,we know the energy distributions of the round and cross beam spots,which show that the smaller aperture radius and longer wavelength of light will cause more significant diffraction.Finally,we analyze the effect of incident angle on the output position of PSD.When the incident light changes with a small angle near the vertical position of the sensitive surface of PSD,the offset of gravity point of the light spot energy is very small,and its effect on the output characteristics of PSD is also small.