System for precisely measuring phase delay of wave plate and implementation method of system

Abstract

The invention relates to a method and a system for precisely measuring phase delay of a wave plate. The system comprises a light source, wherein an optical fiber coupler, a polarizer, a compensator, a sample to be tested, a polaroid, an analyzer, an imaging lens, a monochromator and a detector are arranged sequentially on the forward direction of the light emitted by the light source; the compensator is driven by a motor controlled by a computer to rotate; the output of the detector is transmitted to the computer for data process via a data acquisition card; the computer controls the monochromator through the data acquisition card to select wavelength; and the computer transmits a pulse signal to the motor through the data acquisition card to drive and control the motor to rotate the compensator in fixed step length. The method comprises the following steps of: establishing four non-linear equations by using the phase delay of the wave plate as an unknown parameter on the basis of rotating an ellipsometer of the compensator; and evaluating to obtain the phase delay of the sample to be tested. By the measuring process, the self-calibration of the phase delay of the compensator is realized and the system error caused by inaccurate calibration is eliminated. By a three-step measuring method, the influence of the azimuth angle error of the polarizing component of the system is eliminated.

Description

technical field [0001] The invention belongs to the technical field of polarization optical detection, in particular to a precise measurement method and system suitable for measuring wave plate phase delay. Background technique [0002] The wave plate is an important component in polarization optics technology. It is often used in ellipsometry or optical precision instrument measurement to change the polarization state of light. As the main technical parameter of the wave plate, the phase delay has a very important impact on the experimental results. There are many methods for measuring wave plate phase delay, mainly including: compensation method, ellipsometry, light intensity method, frequency division laser detection method, etc. Among them, the mature ellipsometer (RCE) (see Dill et al. Rotating-Compensator Ellipsometer [P]. United States Patent: 4,053,232, 1977) is often used to measure the phase delay of the wave plate. This method needs to be measured by air ( empty ...

AI Technical Summary

Problems solved by technology

Nevertheless, the azimuth angles of the polarizers in the two areas in the dual-area measurement method are no longer symmetrical due to the difficulty of precisely locating the initial position of the azimuth angle of the polarizer, so that the first-order effect of the azimuth error cannot be completely eliminated

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