Ultra-compact wavelength-division (de)multiplexer on 4H-silicon-carbide-on-insulator platform via inverse design

By employing inverse design with topology optimization, a highly efficient wavelength-division (de)multiplexer (WDM) for the C-band (1550 nm) and L-band (1600 nm) was achieved on a 4H-silicon-carbide-on-insulator (4H-SiCOI) platform. The designed WDM is ultra-compact with a footprint of 8 µm ×4 µm. Experimental results reveal a maximum transmission of -0.76dB (-0.74dB) and an extinction ratio of 17 dB (11 dB) at the C (L) band, with a 3-dB bandwidth of 39 nm (36 nm).