A Method for Extracting Optical Constants and Euler Angles of Anisotropic Materials

Abstract

The invention belongs to the technical field related to the measurement of anisotropic-body materials, and discloses a method for extracting an optical constant and an Euler angle of an anisotropic-body material. The method comprises the following steps of (1) establishing a test system for a to-be-measured sample, and obtaining a measured Mueller matrix spectrum Mm of the to-be-measured sample through the test system; (2) establishing a forward optical model of the to-be-measured sample according to a 4*4 matrix method, and calculating partial transmission matrixes of the to-be-measured sample; (3) calculating a theoretical Mueller matrix spectrum Mc of the to-be-measured sample by combining a fitted initial value of the optical constant and the partial transmission matrixes; and (4) calculating a root-mean-square error between the theoretical Mueller matrix spectrum and the measured spectrum, and optimizing the optical constant to enable the root-mean-square error to be less than a set threshold value, so as to extract the optical constants and Euler angles of the to-be-measured sample under multiple wavelengths. The method provided by the invention is simple in analytic process,higher in measurement accuracy, better in applicability and higher in flexibility.

Description

technical field [0001] The invention belongs to the technical field related to the measurement of anisotropic bulk materials, and more specifically relates to a method for extracting optical constants and Euler angles of anisotropic bulk materials. Background technique [0002] Optical constants and Euler angles are the most important optical properties of anisotropic materials. There are two conventional methods for determining Euler angles: one is to use prior knowledge to determine the position of the optical axis during sample preparation, and then to determine The azimuth angle is used for accurate sample preparation, and then this azimuth angle is directly used as the Euler angle in the inversion process; secondly, the optical constants of anisotropic materials reported in the literature (or select a suitable initial value of the oscillator model) are used as the given fixed value, only by fitting the same measured spectrum as reported in the literature to obtain Euler...

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Problems solved by technology

[0003] However, the above two methods are very easy to cause great errors due to the introduction of the following factors: the azimuth error in the sample preparation process, the difference between the optical constants of the material to be measured and the optical constants of the materials reported in the literature, and the lack of prior knowledge. Dependence of Extracted Euler Angles on Knowledge-Time Fitting Initial Values ​​in Inversion Process

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