Integrated multi-functional silicon photonic engine for long-range FMCW laser ranging
Jing Wang, Lin Zhu, Yan Zuo, De Zhou, Rui Zhu, Hongsong Xu, Hao Wang, Xiong Jiang, Zhiheng Yue, Daohui Pan, Qifeng Liu, Dechuan Zhang
Abstract
Abstract We present an integrated multi-functional silicon photonic engine tailored specifically for long-range frequency-modulated continuous-wave (FMCW) laser ranging systems. The engine integrates a parallel four-channel dual-polarization coherent detection module, an on-chip optical splitting system, a laser nonlinearity calibration module utilizing a large-scale optical delay line (DL), and an on-chip local light optical splitting unit on a single chip. Key components, including germanium-silicon photodetectors, were optimized to achieve high responsivity (1.09 A/W) and low dark current (3.6 nA). The on-chip delay line design achieves an optical time delay of 5.74 ns with improved loss, enabling nonlinearity calibration that enhances signal-to-noise ratio (SNR) and spectrum linewidth. The packaged silicon photonic engine, with a chip size of 2.8 mm × 2.7 mm, demonstrates ranging capabilities up to 200 m with SNR exceeding 10 dB across all four channels. This study represents a new integration solution for the FMCW laser ranging system, providing a robust platform for automotive and other high-precision ranging applications.