Based on a 1/4 λ wave-plate rotation method,the system used a spectrometer as the light source,color filters and a photodetector.

By analyzing the interference of two plane polarized light beam,the principle of elliptic polarization measurement is deduced and the principle of measuring the phase delay of crystals using 1/4 wave plate is introduced.

Study about the impact of 1/2 retardation sheet on the polarization sounding of airborne lidar;

Optimized design of 1/2 retardation sheet for measurement of airborne lidar polarization channels gain ratio;

The basic principle of the laser longitudinal mode splitting is introduced briefly,and the Nd∶YAG laser longitudinal mode splitting produced by placing one and two quarter-wave plates in the cavity of a Nd∶YAG laser is investigated experimentally.

Before being depolarized,the incident linearly polarized light is converted into an elliptical polarized light by a quarter-wave plate and is divided into two or.

A method to calibrate the fast axis of a quarter-wave plate by nulling the foundamental component was proposed and the calibration principle was analyzed.

A quarter wave plate (QWP) is frequently used in a pulse Nd : YAG laser resonator and its function is determined by its location and the direction of the fast axis in the resonator.