On-Chip Reconfigurable Three-Waveguide Coupling Mode Switches on Silica Platform

Reconfigurable mode switches can provide more flexible and advanced data exchange functions for complex on-chip optical networks. A reconfigurable mode-selective optical switch based on adiabatic progressive three-waveguide coupling (TWC) is proposed. As a proof of concept, the switching of E00 (E20)/E10 (E30) dual-mode channels was successfully implemented and demonstrated. At 1550 nm, the insertion losses for E00/E10 and E20/E30 mode switches were lower than 7.86 and 10.76 dB, respectively. These values include the loss of the mode demultiplexer. The crosstalk was lower than −22.84 (−18.28) dB at 1550 nm. The switching rise time (10–90%) and fall time (10–90%) were 0.86 ms and 0.64 ms, respectively. On the silica platform, the scalability of the structural scheme was also verified, and the arbitrary selection and switching of the E00, E10, E20, and E30 modes were achieved via the cascading of TWCs. The device can be used as an important component for the future large-scale integration and flexible switching of on-chip optical networks.