Broadband and Reconfigurable Dual‐Mode Optical Switch with Low Power‐Consumption

Abstract Mode‐division multiplexing (MDM) technology, as a new way to increase the communication capacity of a single wavelength carrier, has attracted increasing attention. As a fundamental building block for MDM communication systems, multimode optical switch is playing an important role for routing the increasingly complex network. However, it is still very challenging to achieve a multimode optical switch with high flexibility and low power‐consumption in a large bandwidth. Here, a 1 × 2 dual‐mode optical switch is proposed and experimentally demonstrated, where the E 11 and E 21 modes can be switched output from either of the two output ports simultaneously or individually with low power‐consumption. For the proposed dual‐mode optical switch, three asymmetric Y‐junctions are used as mode (de)multiplexers, two Mach–Zehnder interferometers form a single‐mode switch matrix, and a 2 × 2 multimode interferometer is used as the waveguide crossing. The device is fabricated with simple photolithography and wet‐etching methods. The measurement results show that the driving powers of the device are lower than 8.4 mW, and the crosstalks are less than −12.4 dB in the wavelength range of 1500–1600 nm. By implementing the dynamic control of resources between the guided modes, the proposed device can greatly improve the flexibility and efficiency of reconfigurable MDM networks.