Ultrafast non-volatile 1x1 optical switch using phase change material Sc_0.2Sb₂Te₃

Phase change materials are widely used in photonic devices due to their extremely large optical properties. Phase change optical switches use the difference in refractive index between amorphous and crystalline states to achieve "on" and "off". In this paper, we design a Si-Sc_0.2Sb₂Te₃ (SST) hybrid waveguide 1x1 optical switch. The finite element method was used to optimize the structural parameters of the device and the modal distribution of TE polarization was calculated. The transmission performance of the device is simulated by the FDTD method. In this case, a very compact, 2 µm long SST shows a large extinction ratio of more than 12 dB and over 100 nm bandwidth operation.