Patent ID: 6546165
Filing Date: 2003-04-08
Classification: G02B,H04J

Abstract:
An optical multiplexing/demultiplexing module comprising:a first optical input section for inputting a first linearly polarized beam; a second optical input section provided at an interval d from the first optical input section for inputting a second linearly polarized beam having a plane of polarization orthogonal to that of the first beam; a uniaxial birefringent crystal for multiplexing the first and second beams; an optical output section for outputting a multiplexed beam multiplexed by the crystal; an optical path converting member for converting at least one of an optical path of the first beam or the second beam and for causing the first or the second beam to enter the crystal; wherein the converting member is arranged for performing the optical path conversion such that a distance D between the respective points of entrance of the first and second beams entering an entrance surface of the crystal is smaller than d; and wherein D is substantially equal to or greater than a sum of twice a spot size of the first beam on the entrance surface plus twice a spot size of the second beam on the entrance surface.