Spatial modulation polarization detection system and design method

Abstract

The invention provides a spatial modulation polarization detection system and a design method, is used for detecting polarization characteristics of a sample to be detected, and belongs to the technical field of optical design. The system comprises a light source, a polarization state generator, a spatial optical filter, a collimating lens, a phase delayer, a polarization state analyzer, a focusing lens, a detector and a data processing module; the system further comprises a quarter-wave plate, and the quarter-wave plate is arranged between the phase delayer and the collimating lens; ad the fast axis azimuth angle of the quarter-wave plate is determined by the maximum contrast ratio of the polarization state coefficient. According to the system, the optimal fast axis azimuth angle of the quarter-wave plate is selected, so that the model parameters in the intensity distribution model have the maximum contrast ratio, a global optimal solution exists in the process of fitting and resolving the polarization state, and the resolving precision of the polarization state is improved.

Description

technical field [0001] The invention belongs to the technical field of polarization measurement, and in particular relates to a space modulation polarization detection system and a design method. Background technique [0002] Polarization is an important property of light, and polarized light is very sensitive to microstructural properties in samples such as optical components, materials, and biological tissues. When light interacts with the sample, processes such as refraction, reflection, and scattering occur, thereby changing the polarization state of the incident light. The ability of the sample to change the polarization state of light is represented by the Mueller Mueller matrix. The Mueller matrix contains all the polarization information of the sample, which can be further decomposed into depolarization, phase retardation, dichroism, fast axis direction angle, optical rotation, etc. The quantifiable polarization parameters that are closely related to the microstruct...

AI Technical Summary

Problems solved by technology

[0005] First, when the wave plate of the polarization state analyzer is rotated multiple times to obtain multiple fast axis azimuths of the wave plate, and the partial derivatives of multiple polarization probability density functions thus obtained have unique zeros at the same time, it is impossible to determine which unique The azimuth angle of the fast axis of the wave plate corresponding to the zero point is optimal, so the above method can only select a suitable polarization state analyzer when several polarization state analyzers are given, and cannot traverse all polarization state analysis modes to find the optimal Polarization Analyzer

[0006] Second, set the constraints as follows: select the variable fast axis azimuth angle of the wave plate of the polarization state analyzer, and fix the direction of the transmission axis of the polarizer to the horizontal direction; therefore, only the difference of the wave plate of the polarization state analyzer is considered in this technology The influence of fast axis azimuth angle on polarization detection does not consider the influence of different rotation angles of polarizers. The polarization state analysis mode obtained by this method only obtains the appropriate quarter-wave plate fast axis azimuth angle in the polarization state analyzer. Ability to obtain suitable polarizer angle

However, this method cannot achieve spatial modulation of the circularly polarized component using only a vortex half-wave plate, so this method cannot directly detect Stokes' s 3 Parameters, only the polarization state detection of fully polarized light can be realized, and the polarization state detection of partially polarized light can not be realized

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