Study on dynamic wavelength matching technology of laser radar based on volume grating narrowband optical filtering

LiDAR is a kind of active detection technology that can accurately and quickly obtain 3D information of targets. However, it is subject to intense noise from the solar background when it operates during the day. In this case, narrow line width lasers and filters are generally used to achieve the effect of suppression of background noise. When both of them are extremely narrow line widths, the SNR of the received signal will be significantly affected if the center wavelengths of the two are mismatched. Therefore, from the perspective of narrowband filtering and wavelength tracking of the transmitted signal by the received signal, a tunable filter receiver and the optical path of the transceiver system of the lidar were designed by using the volume grating, and the tracking of the received wavelength to the transmitted wavelength of the lidar was realized under the condition of narrow filtering bandwidth. Finally, the whole system was actually built in the laboratory to verify the correctness of the system design. At a fixed wavelength and tunable wavelength, the tracking accuracy is better than 2.9 pm. At this time, the received signal intensity is greater than 99.97% of the central wavelength matching condition.