Optical Autocorrelator Based on InSe-Integrated Silicon Waveguide

作者：Yu Zhang, Xiaoqing Chen, Mingwen Zhang, Fang Wang, Yingke Ji, Jianguo Wang, Puhui Zhang, Liang Fang, Yanyan Zhang, Biqiang Jiang, Jinman Ge, Weida Hu, Jianlin Zhao, Xuetao Gan · 发表于：Nano Letters · 年份：2025 · DOI：10.1021/acs.nanolett.5c02520 · 被引用次数：6 · 研究领域：Photonic and Optical Devices、Phase-change materials and chalcogenides、Photorefractive and Nonlinear Optics

We demonstrate an on-chip single-shot autocorrelator by integrating few-layer InSe onto a silicon waveguide. With the strong second-order nonlinearity of InSe, a strong second harmonic generation (SHG) signal happens when counter-propagating pulses overlap within the InSe-integrated silicon waveguide. By mapping the spatial intensity distribution of the SHG signal into the time domain, the temporal profile of the pulse and group index of the waveguide modes were characterized successfully. Benefiting from the large second-order nonlinearity of InSe and the enhanced light–matter interaction provided by the silicon nanophotonic structure, our device can operate with pulse peak power down to 11 mW that is over two orders lower than that of the conventional integrated silicon autocorrelators, reaching a sensitivity of 2.4 × 10 –8 W 2 . Our device demonstrates the promising potential of ultrafast optical pulse measurements in photonic integrated circuits.