Optical waveguide device used in laser detection and ranging system

An optical waveguide device used in a laser ranging system, the optical waveguide device comprising:

• a waveguide inlet configured to receive a first light signal;
• a waveguide body configured to guide the first light signal to transmit in the optical waveguide device;
• and
• a waveguide outlet configured to output a second light signal exited after the first light signal is guided;
• wherein a ratio of the area of the waveguide inlet to that of the waveguide outlet is greater than a first preset ratio, and transmission efficiencies of the optical waveguide device in first and second directions are different, the transmission efficiency in the first direction is greater than a first threshold, the transmission efficiency in the second direction is less than a second threshold.

A lidar system, comprising:

• at least one light source unit configured to emit an emitted light signal, and part of a reflected light signal after the emitted light signal is reflected by at least one target object in a target scene is received by the lidar system as an echo light signal, wherein the emitted light signal contains information about emission start time of the emitted light signal;
• at least one photoelectric conversion unit configured to convert the echo light signal into a received photoelectric signal, wherein the received photoelectric signal contains information about the time when the echo light signal is received;
• at least one light transmission unit configured to receive the emitted light signal and send it to the target scene, and/or receive the echo light signal and send it to the at least one photoelectric conversion unit;
• and
• at least one signal processing unit configured to generate a scan control signal so as to control at least one scanning unit and/or obtain a scan feedback signal from the at least one scanning unit, and to determine at least one of a distance of the target object, a reflectivity of the target object, a directional angle of the target object, and a profile of the target object according to the reflected light signal, the received photoelectric signal, the scan control signal and the scan feedback control signal;
• wherein the at least one light transmission unit comprises:
• the at least one scanning unit configured to change a propagation direction of the emitted light signal and/or the echo light signal;
• at least one receiving lens unit configured to receive the echo light signal;
• at least one optical waveguide unit configured to guide the echo light signal to the at least one photoelectric conversion unit, a ratio of the area of the waveguide inlet to that of the waveguide outlet of the at least one optical waveguide unit is greater than a first preset ratio, and a functional surface of the at least one optical waveguide unit contains a diffuse reflection portion;
• wherein the at least one photoelectric conversion unit is disposed at a corresponding waveguide outlet to receive a light signal exited from the waveguide outlet.