| 摘要 |
A differential interference microscope is capable of accurately measuring bumps on an object surface. A ray from a light source is guided to a polarizer and a birefringent prism in this order. An ordinary ray and an extraordinary ray, split by the birefringent prism, are then guided to an objective lens. The ordinary ray and the extraordinary ray, which have passed through the objective lens, telecentrically illuminate a sample. The ordinary ray and the extraordinary ray, after being reflected by the sample, are guided to the objective lens and the birefringent prism in this order. The composite ray composed by the birefringent prism is guided to an analyzer. A CCD is positioned at the image-forming position of the ray that has passed through the analyzer. Either the analyzer or the polarizer is rotatable about the optical axis of the differential interference microscope. A quantity of light that has passed through the analyzer or the polarizer is measured for every three or more rotation angles and for every picture element of the CCD. The measured quantity of light is Fourier-transformed with respect to the three or more rotation angles to determine the amplitude reflectance distributions and/or the surface contours of the sample.
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