Fast-scanning speed single-photon counting LiDAR based on front focal length modulation.

This Letter presents a method for fast-scanning speed LiDAR based on front focal length modulation in the transmitter, which compensates for the influence of the laser divergence angle on the scanning speed at close range of the long-range LiDAR. According to the thin lens equation for Gaussian beams, the laser divergence angle is affected by the distance from the lens to the object (the waist of the laser beam). The scanning speed of the LiDAR is correlated to the laser divergence angle during LiDAR operation, and the scanning speed can be improved by expanding the laser divergence angle by enlarging the front focal length of the transmitter. Through experimental analysis, the laser dispersion angle modulation of LiDAR can improve the scanning speed under the premise of guaranteeing the target detection performance in close-range detection.

Study of 256 fiber array biaxial LiDAR optical assembly measurements.

This paper presents a method for measuring the optical assembly results based on multi-beam biaxial LiDAR. This method analyzes the optical assembly parameters of a LiDAR system affecting the LiDAR operation, and an experimental measurement system is built using a collimator to simulate the infinity imaging field. An InGaAs infrared camera is used to take pictures of the laser spot from the LiDAR transmitter and receiver, and then fit the laser spot images with Gaussian equations to calculate the biaxial LiDAR optical assembly results. Finally, the possible effecting factors of LiDAR alignment results are analyzed. This method is experimentally proven to achieve the measurement of the optical assembly results of a large scale multi-beam LiDAR. The possibility of further optimizing the measurement method by shaping the transmit laser is also reported.