Lidar and gain device thereof, and laser

A laser, comprising:

• a gain device and an external-cavity mode-selection device, wherein the gain device is butt-coupled to the external-cavity mode-selection device, the gain device comprises an active region and n waveguide segments provided separately and connected in series on one side of the active region, wherein different bias currents are applied to the n waveguide segments, and current modulation signals are applied to at least one waveguide segment except for waveguide segments at two ends of the n waveguide segments, to adjust wide-spectrum gain and dynamic response jointly generated by the active region, wherein n is an integer greater than or equal to 3.

A LiDAR, comprising:

• a light source, a transceiver module, a detection module and an information processing module;
• wherein the light source comprises a laser comprising a gain device and an external-cavity mode-selection device, wherein the gain device is butt-coupled to the external-cavity mode-selection device;
• the gain device comprises an active region and n waveguide segments provided separately and connected in series on one side of the active region, wherein different bias currents are applied to the n waveguide segments, and current modulation signals are applied to at least one waveguide segment except for waveguide segments at two ends of the n waveguide segments, to adjust wide-spectrum gain and dynamic response jointly generated by the active region, wherein n is an integer greater than or equal to 3.