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.

中文翻译：

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基于光子晶体和纳米线波导的模式和密集波分复用混合解复用器

我们提出了一种基于光子晶体 (PhC) 和纳米线波导的用于模式和密集波分复用 (DWDM) 的混合解复用器。设计的解复用器由使用 PhC 腔的 DWDM 模块组成，这些腔由有效的 Aubry-André-Harper (AAH) 双色势定义，模分复用模块使用纳米线波导构建非对称定向耦合器。采用二维时域有限差分法分析解复用器的性能参数。结果表明，1573.0和1572.2 nm的基本横电（TE0）模式和一阶TE（TE1）模式可以同时解复用。插入损耗小于0.6dB，串扰小于-18.6dB。此外，解复用器具有高达 250 nm 的大自由光谱范围，