Polarizing beam splitter and polarizer using the same

Abstract

There are provided an inexpensive polarizing beam splitter having a polarized light beam separating function of a wide range with a simple film construction and a reduced number of laminated film layers, and a polarizer provided with the polarizing beam splitter to arrange natural light into a specific polarized state. A polarizing beam splitteris constructed including a polarized light beam separation filmin which a first polarized light beam Lof a light Lincident at a predetermined angle is transmitted and a second polarized light beam Lof the incident light Lis reflected in a direction different from the above transmitted direction, having any structure of (H2L), (H2L)H, and 2L(H2L)(where m is an integer 3 or more) , each of which is a repeated structure of a basic structure film H2L that, when λrepresents a reference wavelength of 550 nm of the incident light, is constructed of a high refractive-index layer H and low refractive-index layer L each of which has an optical film thickness approximately equal to λ/4; and transparent substratesA,B disposed on the light-entering surfaceA side and on the light-outgoing surfaceB side of the above film, respectively. Also, a polarizer is constructed being provided with the above polarizing beam splitterand is formed by alternately laminating the polarized light beam separation film and transparent substrate to be obliquely cut out.