# Scanning Mirror Benchmarking Platform Based on Two-Dimensional Position Sensitive Detector and Its Accuracy Analysis

## TL;DR

This paper introduces a precise benchmarking platform for MEMS scanning mirrors using a two-dimensional position-sensitive detector to measure performance parameters like deflection angle and resonance frequency.

## Contribution

The novel contribution is a high-accuracy scanning mirror benchmark platform using a two-dimensional PSD and detailed analysis of measurement accuracy.

## Key findings

- The platform can measure deflection angles between −6.34° and +6.34° with high accuracy.
- At a 0.01° deflection angle, the measurement accuracy is 0.00097°, and at 6.34°, it is 0.011°.
- The system accounts for optical alignment and PSD measurement errors in its uncertainty analysis.

## Abstract

A MEMS scanning mirror is a beam scanning device based on MEMS technology, which plays an important role in the fields of Lidar, medical imaging, laser projection display, and so on. The accurate measurement of the scanning mirror index can verify its performance and application scenarios. This paper designed and built a scanning mirror benchmark platform based on a two-dimensional position-sensitive detector (PSD), which can accurately measure the deflection angle, resonance frequency, and angular resolution of the scanning mirror, and described the specific test steps of the scanning mirror parameters, which can meet the two-dimensional measurement. Secondly, this paper analyzed and calculated the angular test uncertainty of the designed test system. After considering the actual optical alignment error and PSD measurement error, when the distance between the PSD and MEMS scanning mirror is 100 mm, the range of mechanical deflection angle that can be measured is (−6.34°, +6.34°). When the mechanical deflection angle of the scanning mirror is 0.01°, the accuracy measured by the test system is 0.00097°, and when the mechanical deflection of the scanning mirror is 6.34°, the accuracy measured by the test system is 0.011°. The test platform has high accuracy and can measure the parameters of the scanning mirror accurately.