Y-branch wavelength demultiplexer based on topological valley photonic crystals. (November 2022)

• Record Type: Journal Article
• Authors: Xu, Yi; Zhou, Wen; Chen, Kaihui; Huang, Xuguang
• Is Part Of: Optics & laser technology. Volume 155(2022)
• Publication Date: 2022-11
• Subjects: Topological insulator waveguides -- Wavelength demultiplexer -- Y-splitter -- Valley photonic crystals; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2022.108422
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: This topological structure can achieve frequency-dependent light splitting. Excellent performance of Y-branch wavelength demultiplexer at telecom bands. The defect has little effect on this device due to the topological protection. Abstract: Inspired by topological insulators in the condensed matter physics, topological photonics is a new paradigm, which is free of light backscattering at sharp waveguide bends due to the topological protection, and shows unidirectional light propagation based on the valley-chiral locking. Herein, we propose a two-channel Y-branch wavelength demultiplexer operating at the telecom band using the topological photonic integrated circuits for the first time. The proposed Y-branch wavelength demultiplexer is designed as adjoining and separating of two different topological interfaces at its input and output ports, respectively. Topological edge states with spectral interleaving can be excited in the two different topological interfaces, and be split into two output ports of the demultiplexer in short and long wavelengths. The Y-branch topological waveguide can be used as a dichroic mirror or a wavelength filter for separating light at two different wavelengths. The proposed topological integrated circuit is immune to structural defects. It is promising for the practical applications of optical interconnects and signal processing on a silicon photonic chip.