To provide a polarized beam splitter by which S polarized beam of desired color can be obtained without using a color filter or the like and to provide its manufacturing method.
The polarized beam splitter is provided with a pair of transparent base bodies 1a, 1b and a multilayer film 2 composed of a high refractive index layer and a low refractive index layer provided between the transparent base bodies 1a, 1b. In this polarized beam splitter, formula (1): nL<nS, nH, formula (2):θ>sin-1 (nL/nS) and formula (3): dLmax<λmax are satisfied (wherein nL denotes a refractive index of the low refractive index layer, nS denotes a refractive index of the transparent base bodies 1a, 1b, nH denotes a refractive index of the high refractive index layer, θ denotes an angle of reflection of light L which is made incident vertically on one transparent base body at an interface with the multilayer film 2, λmax denotes a maximum of using wavelength and dLmax denotes maximum optical layer thickness of the low refractive index layer). Further the number of layers of the multilayer film 2 is 15 or more, transmissivity of P polarized light is 20% or less throughout whole regions of the using wavelength and transmissivity of S polarized light is a predetermined value within a range of the using wavelength.
JP2004047903A | 2004-02-12 |
US5912762A | 1999-06-15 |
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