Polarizing beam splitter and polarizer using the same

摘要

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 splitter 1 is constructed including a polarized light beam separation film 2: in which a first polarized light beam L 1 of a light L 0 incident at a predetermined angle is transmitted and a second polarized light beam L 2 of the incident light L 0 is reflected in a direction different from the above transmitted direction, having any structure of (H2L)^m, (H2L)^mH, and 2L(H2L)^m (where m is an integer 3 or more) , each of which is a repeated structure of a basic structure film H2L that, when lambda₀ represents 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 lambda₀/4; and transparent substrates 3 A, 3 B disposed on the light-entering surface 2 A side and on the light-outgoing surface 2 B side of the above film 2 , respectively. Also, a polarizer is constructed being provided with the above polarizing beam splitter 1 and is formed by alternately laminating the polarized light beam separation film and transparent substrate to be obliquely cut out.