Polarization separating/synthesizing element and optical device using it

Abstract

A polarized-light separating/combining element is obtained which can suppress deviation in a direction of rays (angular error), reduce beam coupling loss and improve extinction ratio. Size reduction and loss lowering is achieved for an optical device (optical circulator or optical switch), to enable manufacture at a low cost and with ease. A polarized-light separating/combining element has a transparent member having flat surfaces parallel with each other on which both parallel surfaces, polarized-light separating/combining films are formed respectively, wherein both polarized-light separating/combining films are faced to air. By using the polarized-light separating/combining element, various kinds of optical devices (optical circulators or optical switches) can be formed. Particularly, it is effective for realizing a low crosstalk characteristic in a matrix optical switch.

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