Compact nonvolatile polarization switch using an asymmetric Sb<sub>2</sub>Se<sub>3</sub>-loaded silicon waveguide
Huimin Jin, Lei Niu, Jiajiu Zheng, Peipeng Xu, Arka Majumdar
Abstract
We propose and simulate a compact (∼29.5 µm-long) nonvolatile polarization switch based on an asymmetric Sb 2 Se 3 -clad silicon photonic waveguide. The polarization state is switched between TM 0 and TE 0 mode by modifying the phase of nonvolatile Sb 2 Se 3 between amorphous and crystalline. When the Sb 2 Se 3 is amorphous, two-mode interference happens in the polarization-rotation section resulting in efficient TE 0 -TM 0 conversion. On the other hand, when the material is in the crystalline state, there is little polarization conversion because the interference between the two hybridized modes is significantly suppressed, and both TE 0 and TM 0 modes go through the device without any change. The designed polarization switch has a high polarization extinction ratio of > 20 dB and an ultra-low excess loss of < 0.22 dB in the wavelength range of 1520-1585 nm for both TE 0 and TM 0 modes.