OPTICAL CIRCULATOR

摘要

Disclosed is a polarization-non-dependent type optical circulator which has: a plurality of polarization separating/coupling means where incident light from outside is separated into two polarized lights with polarization planes orthogonal to each other when the incident light is received by a first end portion and two internally transmitted polarized lights with polarization planes orthogonal to each other are coupled when the two internally transmitted polarized lights are received by a second end portion on the opposite side of the first end portion; a plurality of polarization rotating means, each of which having a first end portion disposed opposite to the second end portion of the polarization separating/coupling means and a second end portion on the opposite side of the first end portion, where two polarized lights with polarization planes orthogonal to each other are rotated to have polarization planes parallel to each other when the two polarized lights are received by the first portion and two internally transmitted polarized lights with polarization planes parallel to each other are rotated to have polarization planes orthogonal to each other when the two internally transmitted polarized lights are received by the second end portion; and an optical path determining means which is disposed on an optical path connected to the second end portion of the plurality of polarization rotating means and outputs two polarized lights with polarization planes parallel to each other to be input to the second end portion of one of the plurality of polarization rotating means to the second end portion of another of the plurality of polarization rotating means or to outside according to the direction of the polarization planes and an optical path through which the two polarized lights are input.