US Patent 9666191 Laser-based system and optical microphone having increased bandwidth

Laser-based system and optical microphone having increased bandwidth. The system includes a laser microphone to transmit a laser beam towards a human speaker; to receive an optical feedback signal reflected back from the human speaker; and to perform self-mixing interferometry. An optical feedback signal bandwidth enhancer improves the bandwidth of the optical feedback signal, to improve the quality of remote speech detection that is based on the optical feedback signal. The bandwidth enhancement utilizes takes into account one or more of: the identity of the face-region hit by the laser beam; the skin color or shade; obstruction of the skin by hair or by accessories; ability to allocate increased processing resources for processing of the optical feedback signal; ability to modify modulation frequency of the optical feedback signal; Signal to Noise Ratio (SNR) estimation; bandwidth estimation; acoustic-optical transmission channel estimation; or other suitable parameters.