Non-volatile 2 × 2 optical switch using multimode interference in an Sb<sub>2</sub>Se<sub>3</sub>-loaded waveguide
Kun Shang, Lei Niu, Huimin Jin, Haoxian Wang, Wei Zhang, Fuwan Gan, Peipeng Xu
Abstract
We propose a non-volatile 2 × 2 photonic switch based on multimode interference in an Sb 2 Se 3 -loaded waveguide. The different modal symmetries of the TE 0 and TE 1 modes supported in the multimode region change their propagation constants distinctly upon the Sb 2 Se 3 phase transition. Through careful optical design and FDTD optimization of the multimode waveguide dimensions, efficient switching is achieved despite the modest index contrast of Sb 2 Se 3 relative to Ge 2 Sb 2 Te 5 . The fabricated optical switch demonstrates favorable characteristics, including low insertion loss of ∼1 dB, a compact length of ∼27 µm, and small cross talk below −15 dB across a 35 nm bandwidth. Such non-volatile and broadband components will be critical for future high-density programmable photonic-integrated circuits for optical communications and signal processing.