| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarization filter which is small in size and inexpensive, which has a wide wavelength region for polarization, which can be used in a UV region and which is suitable for an exposure device for optical alignment. SOLUTION: First and second multilayer films 1, 2 are formed on both surfaces of a transparent substrate 3. The transparent substrate 3 is disposed as tilted by a specified angle with respect to the optical axis of the incident light. The first multilayer film 2 formed on one surface of the transparent substrate 3 is a multilayer film cutting light at short wavelengths, while the second multilayer film 2 formed on the other surface is a multilayer film cutting light at long wavelengths. The first and second multilayer films are applied at a specified distance not to induce interference of the incident light. By this structure, regions for polarization by both of the multilayer films for cutting light at short wavelengths and light at long wavelengths are connected to enlarge the wavelength range of the polarized light compared to a device with each film separately disposed. Or, the first and second multilayer films may be applied on respective two transparent substrates to constitute a polarization filter. COPYRIGHT: (C)2004,JPO
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