Scalable compact mode (de)multiplexer based on asymmetric Y-junctions

Abstract A scalable asymmetric Y-junctions waveguide mode (de)multiplexer ((de)MUX) is theoretically proposed. The high-order mode in the stem is designed to be separated from the lower-order mode and evolves into the fundamental mode in the narrow arm, through waveguide widths optimization by effective index matching and beam propagation method. Within the wavelength range from 1450 to 1630 nm, the four modes (de)MUX with small footprint of 23  ×  3. 2 μ m 2 demonstrates the insertion loss and crosstalk of less than 0.14 dB and -16 dB, respectively. This scheme may be expanded to handle more modes in (de)MUX design.