Dual-Band (O & C-Bands) Two-Mode Multiplexer on the SOI Platform

We demonstrate a dual-band two-mode (de)-multiplexer based on tapered asymmetric directional coupler (ADC). The working principle of the device relies on the conversion of the fundamental transverse electric (TE0) mode to the first order (TE1) mode. A phase-matching condition is applied across the O- and C-bands to broaden the operation wavelength of the device. Measurement performed on a mode division multiplexing (MDM) link formed by a back-to-back connected multiplexer and demultiplexer exhibited an insertion loss of less than 1.2 dB with cross talk better than 16 dB. The response is recorded over dual-bands, each with 100-nm bandwidth covering 1260-1360 nm and 1500–1600 nm (extends to the near L-band). The device is compact with an overall length of 75 μm.