Identity-enabled CDMA LiDAR for massively parallel ranging with a single-element receiver

Light detection and ranging (LiDAR) have emerged as a crucial tool for high-resolution 3D imaging, particularly in autonomous vehicles, remote sensing, and augmented reality. However, the increasing demand for faster acquisition speed and higher resolution in LiDAR systems has highlighted the limitations of traditional mechanical scanning methods. This study introduces a novel wavelength-multiplexed code-division multiple access (CDMA) parallel laser ranging approach with a single-pixel receiver to address these challenges. By leveraging the unique properties of Gold-sequences in a direct-sequence spread spectrum (DSSS) framework, our design enables comprehensive parallelization in detection and ranging activities to significantly enhance system efficiency and user capacity. The proposed coaxial architecture simplifies hardware requirements using a single avalanche photodiode (APD) for multi-reception, reducing susceptibility to ambient noise and external interferences. We demonstrate 3D imaging at 5 m and 10 m, and the experimental results highlight the capability of our CDMA LiDAR system to achieve 40 parallel ranging channels with centimeter-level depth resolution and an angular resolution of 0.03 degree. Furthermore, our system allows for user identification modulation, enabling identity-based ranging among different users. The robustness of our proposed system against interference and speckle noise and near-far signal problems, combined with its potential for miniaturization and integration into chip-scale optics, presents a promising avenue to develop high-performance, compact LiDAR systems suitable for commercial applications.