Micro phase delay measuring device for optical element based on laser feedback

Abstract

The invention relates to a micro phase delay measuring device for an optical element based on laser feedback, belonging to the technical field of laser measurement. The measuring device is characterized in that a double refraction laser feedback system comprising a 632.8nm He-Ne optical maser, an outer reflector and a quarter-wave plate is used to measure the phase delay of the optical element. The optical element to be measured is placed in a laser cavity, and the polarization state of the laser jumps in two orthogonal directions when the outer reflector moves left and right along the laser axis. With the polarization jump, the frequencies of the two eigenstates of the laser mode are different, and the frequency difference thereof is related to the size of phase delay of the laser cavity.The measurement of micro phase delay of the optical element can be realized by the principle. The measuring method of the micro phase delay of the optical element based on laser feedback and an implementation device thereof have the advantages of simple structure, easy assembly and adjustment, high measuring accuracy and low cost.

Description

technical field [0001] The invention relates to a laser feedback-based optical element micro phase delay measurement device, which belongs to the technical field of laser measurement. Background technique [0002] There are many factors that can cause phase anisotropy in optical components, such as: residual stress, birefringence, laser gain, and film non-uniformity. At present, there are many high-precision optical element phase delay measurement methods at home and abroad, but most of them are based on measuring quarter-wave plates, and there is no special method and device for measuring the small phase delay of optical elements. At present, the typical wave plate measurement methods are as follows. [0003] 1. Rotational extinction method [0004] The fast axis of a standard 1 / 4 wave plate is at a 45° angle to the polarization direction of the polarizer, and the fast axis of the measured 1 / 4 wave plate is in the same direction as the polarization direction of the polari...

AI Technical Summary

Problems solved by technology

This increases the complexity of the measurement system. Due to the introduction of more instrument errors and azimuth adjustment errors in the measurement process, the further improvement of measurement accuracy is limited, and most of them do not have the measurement of small phase delays of optical components.

Images