Polarization-dependent four-port fiber optical circulator based on the Sagnac effect.

Abstract

We demonstrate theoretically and experimentally a fiber optical circulator with a rotating ring interferometer based on the Sagnac effect. A ratio of 104:1 in light transmittance in the forward and backward directions between the same input/output ports of the circulator was experimentally demonstrated. The optical isolation in the backward direction was 24 dB.