| Summary: | 碩士 === 國立交通大學 === 光電工程系所 === 93 === The Photoelastic Modulation Ellipsometer is used to measure an artificial circular polarizer (CP), which is a combination of a linear polarizer and a retarder. The multi-wavelength measurement technique is built up by using the Kr-Ar tunable laser.
In the beginning, the azimuth direction of optical axis of this CP is roughly determined by comparing the theoretical model with its measurement for a single wavelength. The parameters: linear dichroism (LD), phase retardation and the azimuth angle between the linear polarizer and retarder (γ) are measured by fitting its 1st and 2nd harmonics signals of various azimuth positions of analyzer for the Kr-Ar tunable laser. Although the measured �� is independent of wavelength but it is not at 45o, and its phase retardation and LD are almost the same for every wavelength. Finally by comparing the theoretical transmission, which is derived by substituting its measured parameters, to its measured transmission under various azimuth positions of analyzer, we observed a well fitted result for every wavelength.
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