Ultra low-loss 1×2 multiplexer using thin-film filters on polymer integration platform

Abstract

Compact 1×2 wavelength multiplexer modules employing thin-film filters integrated into polymer planar waveguide circuits are presented. The modules also feature on-chip deep-etched U-grooves for precise fibre-chip coupling. Insertion loss <1 dB, crosstalk <−30 dB, and return loss <−50 dB have been achieved by various technological optimisations.