Multimode Reconfigurable Thermo-Optical Switch Array Based on Silica Platform

A multimode reconfigurable non-blocking thermo-optical switch array is proposed and experimentally demonstrated based on silica platform. Four mode (de)multiplexers and a 4 × 4 non-blocking thermo-optical switch are integrated monolithically. Four mode lights, including E
₀₀
, E
₁₀
, E
₂₀
, and E
₃₀
, are generated and transported back fundamental mode before launching into switch array. The lights in switch are able to different outputs. The 2 × 2 optical switch unit is a balanced Mach-Zehnder interferometer based on a directional coupler structure, with heated electrodes above two modulation arms. At 1550 nm, with mode (de)multiplexers introduced, the average fiber to fiber losses are increased to 3.05 dB ± 0.31 dB and 2.75 dB ± 1.50 dB from 2.69 dB ± 1.18 dB and 2.68 dB ± 0.93 dB in the “all-cross” and “all-bar” states, respectively. The crosstalk is deteriorated to –12.62 dB from –19.37 dB at 1550 nm. The hybrid reconfigurable system on chip can work among C-band. The chip proves the commercial possible of multimode reconfigurable system on silica platform. Based on photonics integrated circuit platform, compact and large-scale multimode system on chip is promising.