Realization of nonvolatile polarization switch based on right-angle Sb2S3 embedded in 4H-SiC waveguide

A nonvolatile polarization switch is proposed numerically assisted by right-angle Sb₂S₃ inlaid in a strip 4H-SiC waveguide. The polarization of incident light can be engineered by the phase states of Sb₂S₃. When the Sb₂S₃ is crystalline, a TE0-TM0 polarization conversion is achieved with insertion loss (IL) of 0.22 dB and polarization conversion efficiency (PCE) of 98.36 % at the wavelength of 1550 nm. As long as the Sb₂S₃ is switched to the amorphous state, the polarization conversion effect becomes negligible with IL < 0.014 dB and PCE < 3.16 % across 1500–1600 nm waveband. Moreover, the robustness analysis demonstrates that the proposed structure maintains its functionality within ± 10 nm deviations of Δh, Δw, Δl, and Δd. The low-loss Sb₂S₃-assisted polarization switch offers a novel methodology for nonvolatile switching to programmable integrated optics, which can be deployed in polarization manipulation and neuromorphic optical computing.