Silicon-Nanowire-Type Polarization-Diversified CWDM Demultiplexer for Low Polarization Crosstalk

Coarse wavelength division multiplexing (CWDM)-targeted novel silicon (Si)-nanowire-type polarization-diversified optical demultiplexers were numerically analyzed and experimentally verified. The demultiplexer comprised a hybrid mode conversion-type polarization splitter rotator (PSR) delayed Mach–Zehnder interferometric demultiplexer. Si-nanowire-based devices fabricated using commercially available Si photonics foundry process, exhibiting nearly identical spectral responses regardless of the states input signals under PSR. experiment demonstrated low insertion loss 1.0 dB polarization-dependent dB, effectively suppressing crosstalk from other channels by less than −15 dB. Furthermore, TM-mode rejection-filter-integrated was designed validated to mitigate unwanted TM-mode-related that arose It exhibited an improved rejection efficiency −25 −50 within whole CWDM range.