Noise-Robust Quantum LiDAR Using Temporally Long Single Photons and Phase Modulation

Yen-Cheng Shih^1,2*, Wen-Chia Lo¹, Fan-Yi Lin², Chih-Sung Chuu¹

¹Department of Physics, National Tsing Hua University, HsinChu, Taiwan
²Department of Otics and Photonics, National Tsing Hua University, HsinChu, Taiwan

* Presenter:Yen-Cheng Shih, email:jamesshih268@gmail.com

Quantum LiDAR combines quantum light sources with LiDAR techniques, leveraging quantum properties for enhanced sensing. However, strong background noise and weak reflections often suppress quantum signals. Inspired by the spread-spectrum technique, we implement synchronized phase modulation and demodulation to encode and retrieve quantum photons while filtering incoherent noise. Experimental results demonstrate a 17.9 dB signal-to-noise ratio (SNR) improvement under conditions where noise exceeds the signal by two orders of magnitude. This approach enhances the practicality of quantum LiDAR and provides a scalable path toward real-world quantum sensing.

Keywords: Quantum Illumination, Quantum LiDAR, Quantum optics, Spread spectrum technique