Silicon High-Order Mode (De)Multiplexer on Single Polarization

Mode-division multiplexing on an integrated photonic chip is critical for future optical networks. High-order mode multiplexing is desired to increase the transmission capacity. Here, we propose and experimentally demonstrate a silicon on-chip high-order mode (de)multiplexer using subwavelength grating (SWG) structure, which supports 11-mode (de)multiplexing on a TE-polarized light (TE0-TE10). The proposed mode (de)multiplexer comprises three directional couplers and seven SWG-based directional couplers. Measurement results show that all the 11 channels have low crosstalk values (-15.4 to -26.4 dB) and low insertion losses (0.1 to 2.6 dB) at 1545 nm. To the best of our knowledge, our device achieves the highest-order-mode (de)multiplexing on a silicon photonic chip.