An improvement to the infinite integration method Based on quadrant detector

Abstract

In this study, we propose a new method to improve the position measurement accuracy of the traditional infinite integral method (IIM) based on a quadrant detector (QD). First, the error source of the IIM is analysed in depth. Then, the influence of the detector size and gap width was considered to obtain a modified integration area. Thus, a new analytical expression was obtained. We performed several sets of simulations to test the validity of our proposed method, and the root-mean-square errors under different radii were all less than 5×10-5mm. The experimental results show that when compared to IIM and the calibrated infinite integral method (CIIM), our novel method reduces error by 98.1% and 85.3%, respectively. One of the advantages of this technique is its simplicity; it requires fewer parameters and does not require pre-calibration compared with the fitting method. Therefore, this technique has the potential to be employed in space laser communication systems, optical tweezers, and precision measurements.