Huang Xin, Hong Yu, Li Zheng-Ping, Xu Feihu
Opt Lett. 2022 Jul 15;47(14):3568-3571. doi: 10.1364/OL.463007.
Frequency-modulated continuous-wave (FMCW) light detection and ranging (LIDAR), which offers high depth resolution and immunity to environmental disturbances, has emerged as a strong candidate technology for active imaging applications. In general, hundreds of photons per pixel are required for accurate three-dimensional (3D) imaging. When it comes to the low-flux regime, however, depth estimation has limited robustness. To cope with this, we propose and demonstrate a photon-efficient approach for FMCW LIDAR. We first construct a FMCW LIDAR setup based on single-photon detectors where only a weak local oscillator is needed for the coherent detection. Further, to realize photon-efficient imaging, our approach borrows the data from neighboring pixels to enhance depth estimates, and employs a total-variation seminorm to smooth out the noise on the recovered depth map. Both simulation and experiment results show that our approach can produce high-quality 3D images from ∼10 signal photons per pixel, increasing the photon efficiency by 10-fold over the traditional processing method. The high photon efficiency will be valuable for low-power and rapid FMCW applications.
调频连续波（FMCW）激光雷达具有高深度分辨率且不受环境干扰影响，已成为有源成像应用的有力候选技术。一般来说，精确的三维（3D）成像每个像素需要数百个光子。然而，在低通量情况下，深度估计的稳健性有限。为解决这一问题，我们提出并演示了一种用于FMCW激光雷达的高效光子方法。我们首先基于单光子探测器构建了一个FMCW激光雷达装置，相干检测仅需一个弱本地振荡器。此外，为实现高效光子成像，我们的方法借用相邻像素的数据来增强深度估计，并采用全变差半范数来平滑恢复深度图上的噪声。仿真和实验结果均表明，我们的方法每个像素从约10个信号光子就能生成高质量的3D图像，相比传统处理方法，光子效率提高了10倍。这种高光子效率对于低功率和快速FMCW应用将具有重要价值。
