| 摘要 |
PROBLEM TO BE SOLVED: To provide a wavelength filter for selectively extracting light at different wavelengths or selectively eliminating light at a specified wavelength. SOLUTION: The wavelength filter 31 comprises phase plates 33a to 33c placed between a plurality of polarizers 32a to 32d along an optical path. The transmissive face of each phase plate is segmented into a plurality of regions, each region has a thickness different from others so as to function as a wavelength plate having a transmission spectral wavelength different from others. The thickness of each region at the same vertical and horizontal position (i, j) of each phase plate is set to produce a geometrical progression dij, 2dij, 4dij with a geometric ratio of 2. Consequently, when white light is made incident on the wavelength filter, light at different transmission wavelengths, that is, light in colors different by the vertical and horizontal position of each region exits. Thereby, light at different wavelengths can be selected and synthesized, or light at a specified wavelength can be eliminated from the light of the light source. COPYRIGHT: (C)2009,JPO&INPIT
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