US Patent 11506762 Optical module comprising an optical waveguide with reference light path

An optical device includes a substrate including an optical waveguide running through the substrate. An optical transmitter mounted on the substrate in a first location includes at least one optical emitter, which emits a primary beam of optical radiation toward a target and emits a secondary beam of the optical radiation into the optical waveguide. An optical receiver mounted on the substrate in a second location includes at least one optical sensor, which receives the optical radiation that is reflected from the target and outputs a primary signal in response thereto, and receives the secondary beam of the optical radiation from the waveguide and outputs a reference signal in response to the secondary beam. A processor receives and processes the primary signal and the reference signal in order to extract information with respect to the target.