Optical interference ranging sensor

An optical interference ranging sensor comprising:

• a light source configured to project light while changing a wavelength;
• an interferometer that is supplied with light projected from the light source, and is configured to generate interference light based on measurement light that is illuminated onto a measurement target by a sensor head and reflected, and reference light that follows an optical path at least partially different from an optical path of the measurement light;
• a light receiver configured to receive the interference light from the interferometer and convert the interference light into an electric signal;
• and
• a processing unit configured to calculate a distance from the sensor head to the measurement target on a basis of the electric signal,
• wherein
• the interferometer comprises a light projecting channel configured to propagate light supplied from the light source toward the sensor head and irradiate the measurement target with the light from the sensor head, and a plurality of light receiving channels configured to receive the measurement light reflected by the measurement target and propagate the measurement light toward the light receiver, and
• at least one of the light projecting channel and the plurality of light receiving channels further propagates the reference light.