Lidar

A lidar comprising:

• a CW laser light source that oscillates a plurality of CW laser light rays with different wavelengths;
• an optical branching unit that splits the CW laser light oscillated by the CW laser light source;
• a light modulator that modulates first CW laser light split by the optical branching unit;
• an optical fiber amplifier that amplifies the laser light modulated by the light modulator;
• a transmit-receive optical system that irradiates a target with the laser light amplified by the optical fiber amplifier, and that receives scattered light of the laser light by the target;
• an optical multiplexer that mixes the scattered light received by the transmit-receive optical system and second CW laser light split by the optical branching unit, and that outputs mixed light of the scattered light and the CW laser light;
• a photodetector that receives the mixed light output from the optical multiplexer, and that detects beat signals of the scattered light and the CW laser light;
• and
• an information extractor that extracts information about the target from the beat signals detected with the photodetector, wherein
• propagation optical paths of light within the lidar are composed of an optical fiber, and the beat signals detected by the photodetector are superposition of spectral components of the beat signals derived from the plurality of CW laser light rays with different wavelengths.