Polarization-independent waveguide optical isolator based on nonreciprocal phase shift

A polarization-independent waveguide optical isolator based on nonreciprocal interference is proposed. The design uses simultaneous TE and TM nonreciprocal phase shifts obtained from geometric asymmetry in horizontal and vertical axes of waveguide cross section along with opposing transverse and vertical magnetic fields in interferometer arms. A design to achieve such an isolator is described. Both TE and TM nonreciprocal phase shifts comparable to the theoretical counterparts have also been experimentally observed from a single waveguide.