[论文解读] SiN-on-SOI Optical Phased Array LiDAR for Ultra-Wide Field of View and 4D Sensing

Baisong Chen, Yingzhi Li+12 more|arXiv (Cornell University)|Jan 9, 2024

Advanced Optical Sensing Technologies参考文献 33被引用 6

一句话总结

论文提出一种 SiN-on-SOI 光学相控阵 LiDAR 设计，具备 160° 超宽视场和基于 Vernier 的收发器用于 4D 感知，使用 FMCW LiDAR 实现均匀波束质量和 5.5-mm 测距。

ABSTRACT

Three-dimensional (3D) imaging techniques are facilitating the autonomous vehicles to build intelligent system. Optical phased arrays (OPAs) featured by all solid-state configurations are becoming a promising solution for 3D imaging. However, majority of state-of-art OPAs commonly suffer from severe power degradation at the edge of field of view (FoV), resulting in limited effective FoV and deteriorating 3D imaging quality. Here, we synergize chained grating antenna and vernier concept to design a novel OPA for realizing a record wide 160°-FoV 3D imaging. By virtue of the chained antenna, the OPA exhibits less than 3-dB beam power variation within the 160° FoV. In addition, two OPAs with different pitch are integrated monolithically to form a quasi-coaxial Vernier OPA transceiver. With the aid of flat beam power profile provided by the chained antennas, the OPA exhibits uniform beam quality at an arbitrary steering angle. The superior beam steering performance enables the OPA to accomplish 160° wide-FoV 3D imaging based on the frequency-modulated continuous-wave (FMCW) LiDAR scheme. The ranging accuracy is 5.5-mm. Moreover, the OPA is also applied to velocity measurement for 4D sensing. To our best knowledge, it is the first experimental implementation of a Vernier OPA LiDAR on 3D imaging to achieve a remarkable FoV.

研究动机与目标

• 以固态 OPA 实现广域视场内保持光束功率的自主成像动机
• 提出 chained grating antenna 与 Vernier 概念，以在不超过 3-dB 的功率变化下实现 160° 的视场
• 将两组不同间距的 OPA 在同一衬底上集成，形成准同轴 Vernier OPA 收发器
• 展示 FMCW LiDAR 实现 3D 成像与速度测量（4D 感知）

提出的方法

• 设计 chained grating antenna，以在广域偏转角范围内平整波束功率
• 通过集成两组不同间距的 OPA 实现 Vernier OPA 架构，实现准同轴工作
• 将 FMCW LiDAR 应用于具有 5.5-mm 精度的 3D 测距
• 在任意偏转角实现均匀波束质量，原因在于平坦的波束功率分布
• 对 Vernier OPA LiDAR 的广域 FoV 3D 成像进行实验演示

实验结果

研究问题

• RQ1 链式光栅天线能否在超宽 FoV 内提供均匀的波束功率？
• RQ2 Vernier OPA 收发器是否能实现 160° FoV 的准同轴波束偏转以实现 3D 成像？
• RQ3 使用所提 OPA 的 FMCW LiDAR 能实现的测距精度是多少？
• RQ4 系统是否能够通过同时测量速度实现 4D 感知？

主要发现

• 在场内实现 160° FoV 且跨场的波束功率变化小于 3 dB
• 由于平坦的波束功率分布，在任意偏转角实现均匀波束质量
• FMCW LiDAR 配置下的测距精度为 5.5 mm
• 首次在广域 FoV 的 3D 成像中实现 Vernier OPA LiDAR 的实验应用
• 两组不同间距的 OPA 在同一衬底上单片集成，形成准同轴 Vernier 收发器