Elimination of phase-matching requirement for optical waveguide isolator

A novel optical waveguide isolator based on self-phase compensated TE–TM mode conversion was proposed. In this work, the troublesome phase-match condition for the TE–TM mode conversion is eliminated without degradation on the performances. An isolator based on this mechanism is designed and simulated. An insertion loss of −0.1 dB and an isolation of −25 dB was obtained. The tolerance of fabrication and bandwidth of the isolator was also discussed.