High-resolution displacement sensor based on variable spacing grating

Abstract

Compared with the traditional electromagnetic displacement sensor, the optical sensor has the advantages of reduced size and anti-electromagnetic interference. The increasing demand for high-resolution displacement sensors in today's production and research environments has led to the rapid development of variable spacing grating displacement sensors. The principle of variable spacing grating displacement sensor is verified by experiments, and the reliability of the sensor is proved. Based on the theoretical analysis of the linear density formula of variable spacing grating, we proposes a new displacement sensor optimization method. The method is demonstrated by a series of experiments. The main component of the displacement sensor adopts a variable spacing blazed grating in order to concentrate on the first energy level by the energy of the grating diffraction to improve diffraction efficiency. This paper analyzes the correlation between the resolution of the displacement sensor and the resolution of the grating and the resolution of the spectrometer and by experiment we further prove that the smaller the grating spacing is, the stronger the resolution of the grating. Theoretical analysis shows that by increasing the grating spacing variation, the linear density formulas of the variable spacing gratings can be optimized to achieve a 50mm range 0.02mm resolution