Hybrid demultiplexer for mode and dense wavelength division multiplexing based on photonic crystal and nanowire waveguides

Abstract

We propose a hybrid demultiplexer for mode and dense wavelength division multiplexing (DWDM) based on photonic crystal (PhC) and nanowire waveguides. The designed demultiplexer consists of DWDM module using PhC cavities that are defined by an effective Aubry-André-Harper (AAH) bichromatic potential and mode division multiplexing module constructing of asymmetric directional coupler using nanowire waveguides. The performance parameters of the demultiplexer are analysed by two-dimensional finite-difference time-domain method. The results show that the fundamental transverse electric (TE0) modes and first-order TE (TE1) modes of 1573.0 and 1572.2 nm can be demultiplexed simultaneously. The insertion loss is smaller than 0.6 dB, and the crosstalk is smaller than −18.6 dB. Besides, the demultiplexer has a large free spectral range up to 250 nm, which can almost cover the whole range of DWDM system.