摘要 |
An improved aligner detector is provided. The improved aligner detector includes, a detector, several electrooptic modulators, and a refractor set, which includes several wedge patterns. Each of the electrooptic modulators includes a double-refraction transistor, which has a property of double refraction. By applying a special voltage on the double-refraction transistors, the double-refraction transistors can become transparent or opaque. Thereby, the electrooptic modulators can select a desired order of the diffraction light ray. The selected diffraction light ray is refracted by the refractor set to the detector for analysis.
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