Laser source fluctuation compensation method and high-precision location algorithm for laser positioning technology based on quadrant photodetectors

This paper presents a study on the spot location method and system based on QPDs. We construct a mathematical model of the relationship between spot position variations and detector responses, systematically analyzing the impact of the spot size and detector parameters on spot location accuracy. We propose an ultra-precision Gaussian spot location algorithm based on QPDs, along with a common-path laser light source fluctuation error compensation structure and method, and validated the method through simulation experiments. The experimental results show that this scheme can achieve submicron level spot positioning accuracy. In the measurement range of 1 mm, the measurement error after compensation is reduced by 97% compared to before compensation. Additionally, the repeatability and stability demonstrate excellent performance. This study provides a laser light source fluctuation error compensation method and an ultra-precision Gaussian spot location algorithm based on QPDs for laser measurement technology, significantly improving measurement accuracy and environmental interference resistance.