椭圆光斑在四象限探测器定位算法的研究

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中图分类号：TN249；TN247文献标志码：A

Research on localization algorithm of elliptical spot in four quadrant detector

HAOLinjie，MA Junshan，JINTao （School of Optical-Electrical and Computer Engineering， University of Shanghai for Science and Technology，Shanghai200093，China）

Abstract： In order to improve the measurement accuracy of the elliptical Gaussian spot position in the four quadrant detector and the position detection accuracy of the elliptical spot and the center coordinate of the four quadrant detector with an offset rotation angle， a localization algorithm for the elliptical Gaussian spot is proposed. An eliptical light spot with Gaussian distribution was used as the incident light spot model， and infinite integral fiting algorithm and the least squares method were used to fit the optimal analytical expression. In order to establish all models of elliptical spot in the four quadrant detector， polynomial fiting was performed on the offset angle to simplify the calculation of the algorithm for locating the offset angle between the elliptical spot and the center coordinate of the four quadrant detector. Finally，based on simulation，the fiting relationship between the offset angle and the localization algorithm was determined. The positioning accuracy of the algorithm can reach sub-micron level， providing a theoretical basis for the localization algorithm of elliptical spots.

Keywords： four quadrant detector; elliptical spot; offset angle; localization algorithm; Gaussian spot

引言

1四象限探测器光斑定位原理和算法

四象限探测器（four quadrant detector，FQD）是由4个基本相同的光电二极管组成，用来定位外部投射光斑相对四象限探测器中心的位置]。（剩余7882字）