Complete magneto-optical waveguide mode conversion in Cd1−xMnxTe waveguide on GaAs substrate

Complete magneto-optical mode conversion was attained in a waveguide of diluted magnetic semiconductor ${\mathrm{Cd}}_{\text{1−x}}{\mathrm{Mn}}_x\mathrm{Te}$ grown on GaAs substrate. Mode conversion ratio $\text{98\%±2\%}$ under a magnetic field of 5 kG was achieved in the waveguide with graded-refractive-index clad layer. The ${\mathrm{Cd}}_{\text{1−x}}{\mathrm{Mn}}_x\mathrm{Te}$ waveguide showed an optical loss below 1 dB/cm, and a high magneto-optical figure-of-merit, 200 deg/dB/kG at $\text{λ=730\hspace{0.17em}}\mathrm{nm}.$ High efficiency magneto-optical mode conversion in a waveguide grown on a semiconductor substrate shows the feasibility of monolithical integration of an optical isolator with semiconductor optoelectronic devices.