Analysis of polarization modulation laser ranging principle

摘要

Based on pulsed time-of-flight method, polarization-modulated laser ranging technology use electro-optic modulation technology to realize time resolution, and optical distances are used to extract target distance information, which can effectively reduce the distance measurement errors introduced by photoelectric conversion and electrical signal processing systems. The requirement for detector bandwidth is reduced, high-speed timing circuits do not need to be designed, and long-distance, high-precision ranging is achieved. In this dissertation, the principle of polarization-modulated laser ranging is studied. The basic structure of ranging system is analyzed through the combination of theoretical analysis, simulation and experimental verification. Based on this, the time-resolving principle of the electro-optic modulator based on the linear electro-optic effect of the crystal is analyzed using the refractive index ellipsoid theory. The distance ranging selection method is proposed for the problem of limited range of the system. Finally, the correspondence between the intensity of the polarized light and the modulation time is verified by experiments, which provides a theoretical basis for the application of polarization modulation laser ranging technology.