Electro-optic reconfigurable two-mode (de)multiplexer on thin-film lithium niobate

We propose and demonstrate a compact electro-optic reconfigurable two-mode (de)multiplexer using the configuration of cascaded Mach–Zehnder interferometers formed on thin-film X-cut lithium niobate on silica. Our fabricated device, which is 9.5-mm long, can spatially switch between the two transverse-electric modes with an efficiency higher than 98% from 1530–1560 nm and beyond at an applied voltage of 6.5 V. The switching speed is faster than 30 ns. Our proposed mode switch could find applications in fiber-based and on-chip mode-division-multiplexing systems.