Research progress in high-precision spot position detection technology based on the four-quadrant detector

The spot position detection technology based on the four-quadrant detector plays an important role in fields such as laser semi-active guidance, space laser communication, medicine, and precision measurement. The paper systematically summarizes the research progress of high-precision spot position detection technology based on the sum-and-difference algorithm model. First, the improved algorithm models under four conditions are discussed, namely the circular spot and uniform distribution, the circular spot and Gaussian distribution, the elliptical spot and uniform distribution, and the elliptical spot and Gaussian distribution. Further optimization algorithms based on these four models are also introduced. On this basis, although the detection accuracy has been significantly improved, there are still other factors that affect measurement accuracy in practical applications, such as inconsistent quadrant responsivity, noise, atmospheric turbulence, etc. These factors and their influencing trends or correction methods are classified and summarized. With the development of hardware processing capabilities, more new signal processing methods are being used to improve detection accuracy or precision, such as the digital lock-in amplifier method, the neural network method, the Kalman filtering method, etc. Some of these signal processing methods and their positive effects are introduced. Finally, prospects for future development are discussed.