Polarization-mode controlled nonreciprocal optical waveguide device and optical isolator/optical circulator using thereof

A polarization-mode controlled nonreciprocal optical waveguide device to control the polarization mode depending on the polarization of input optical signal comprising:

• an optical waveguide of relatively high refractive index for optical signal transmission;
• cladding layers surrounding the above optical waveguide;
• one side cladding layer of the above optical waveguide that is made of magneto-optic films with a relatively low refractive index;
• a waveguide mode converter converting the waveguide mode based on the optical signal polarization that is positioned before the optical signal enters the waveguide section with the above magneto-optic film-clad layer to minimize optical loss,
• an input side polarization-mode converter that maximizes the magneto-optic effect by converting the optical signal's polarization when it enters the waveguide section with the magneto-optic film-clad layer,
• an output side polarization-mode converter that minimizes optical loss by converting the optical signal's polarization before it exits the waveguide section with the magneto-optic film-clad layer.