A Tunable Multichannel Filter Based on Photonic Crystal

To solve the problems of complex structure, single wavelength download and large size of multichannel filter, a novel ultrasmall tunable multichannel filter based onphotonic crystal (PC) is proposed. The filter consists of an input waveguide, four output waveguides, four hexagonal resonators, four point defects and reflection structures, which can drop eight different wavelength signals at the same time. The wavelength range covers 1310 nm-1510 nm, and the transmission efficiency is greater than 99%. Because the hexagonal resonator material is composed of the phase change material(PCM) Ge2Sb2Se4Te1 (GSS4T1), by changing the refractive index of the phase change material, different wavelengths can be dropped in the same resonator. Therefore, the device size of the filter is only 74.05 μm2, the maximum insertion loss is only 0.0674 dB, and the minimum is 0.0013 dB. The quality factor at 1445.51 nm is as high as 2251. The multichannel tunable photonic crystal filter(PCF) proposed in this paper has the advantages of diversified down-channel wavelengths, high transmission efficiency, small size, and low insertion loss. It is suitable for large-scale integrated circuits and has important application prospects in reconfigurable wavelength division multiplexing for optical networks on chips (ONoCs).