Broadband two-mode multiplexer with taper-etched directional coupler on SOI platform

We propose an original two-mode (TE0/TE1) division multiplexer using a taper-etched directional coupler. The multiplexer has a low insertion loss of -0.1 dB within C-band with a minimum loss of -0.05 dB, a modal crosstalk below -40 dB and a robust fabrication tolerance (>100 nm).