A Polarization-Insensitive High-Resolution Micro-Spectrometer Using ( N + 3) × ( N + 3) Arrayed Waveguide Grating On SOI Platform

作者：Jun Zou, Lingfeng Li, Yuan Zhuang, Changhui Wang, Ming Zhang, Zichun Le, Xuyang Wang, Gaozhe Cai, Shilun Feng, Jian‐Jun He · 发表于：Journal of Lightwave Technology · 年份：2022 · DOI：10.1109/jlt.2022.3209233 · 被引用次数：20 · 研究领域：Photonic and Optical Devices、Advanced Fiber Optic Sensors、Acoustic Wave Resonator Technologies

Ultra-compact on-chip spectrometers with high resolution and large bandwidth play a crucial role in miniaturized spectroscopic analysis systems. Here we present a novel polarization-insensitive micro-spectrometer with high resolution and large bandwidth based on a (N+ 3) × (N+ 3) arrayed waveguide grating (AWG) on silicon-on-insulator (SOI) platform. The proposed AWG can be viewed as two same 3 ×NAWGs with each one having three input waveguides with channel spacing of 4/3 ΔλandNoutput waveguides with channel spacing of Δλ. The three input waveguides are time division multiplexed, i.e., they are excited one by one in sequence. As a result, combining all spectral responses of each input, a micro-spectrometer with channel wavelength spacing enhanced to one-third Δλand channel number enlarged to 3 × (N– 2) is achieved, only usingNoutput channels. The polarization diversity scheme is utilized to address the polarization sensitive issue of silicon nano-waveguide, i.e., the AWG operates at a counter-propagating manner to process each polarization, respectively. In experiment, we demonstrate a micro-spectrometer with 81 channels and channel wavelength spacing of 0.4 nm by employing a 32 × 32 AWG on the SOI platform. The footprint of the fabricated micro-spectrometer is only 1.1 × 2.35 mm2. Experimental results show that the spectrometer has on-chip losses ranging from –5.8 to –2.5 dB, noise level of better than 17 dB, polarization dependent wavelength shift (PDλ) of less than 0.07 nm...