A Programmable All-Optical Delay Array for Light Detection and Ranging Scene Generation

Light detection and ranging (LiDAR) scene generator is an important device in the LiDAR guidance hardware-in-the-loop (HWIL) simulation system. It generates simulated optical LiDAR scenes under laboratory conditions. A simulated LiDAR scene consists of an array of laser return signals with different intensities and time delays. The intensity of a return signal is determined by the target albedo and the target distance. The time delay of a return signal is determined by the target distance. A time delay array system is crucial for the LiDAR scene generation. In this paper, a programmable all-optical delay array system using an optical true-time-delay (OTTD) method is proposed. It can generate laser return signals with large-signal array size, long delay range, and high delay resolution. The signal array size of the generated LiDAR scene is 32 x 32. The depth of field (DOF) of the LiDAR scene is 19.2 m, which can be placed at different distances from 5.1 to 2481.6 m. The distance resolution is 0.3 m. The all-optical delay array system can also be extended to support tests of the LiDAR guidance systems with larger sensor arrays.