Non-reciprocal optical phase shifter based on the Sagnac effect and its implementation as an optical isolator

This work describes the operation of a non-reciprocal optical phase shifter (NRPS) based on the Sagnac effect and provides examples of its usage through integration into various optical circuits. The origin of the occurrence of the phase shift was discussed and experimentally validated. The scheme of a non-magnetic optical isolator with NRPS embedded in a Sagnac interferometer was experimentally demonstrated. A ratio of 110:1 in light transmittance between the forward and backward directions was obtained.