Abstract: Laser-based devices utilizing temperature modulation for improved self-mix sensing. A self-mix laser unit includes: an active region having a first side and a second, opposite, side; a p-type Distributed Bragg Reflector (DBR) region, which is in direct touch with said first side of the active region; an n-type DBR region, which is in direct touch with the second side of the active region; and an n-type or p-type or other substrate. A heating unit provides modulated heating to the active region, either directly via an electrical resistor within the active region; or indirectly by passing or propagating modulated heat through one of the DBR regions or through the substrate. The modulated heating improves the laser-based self-mix signal.

Abstract: A system and method for generating, enhancing, and detecting the amplitude and phase modulation of a laser under a condition of self-mixing is provided. The system may comprise a laser and a detector to extract the characteristic self-mix signal, which is then interpreted using algorithms implemented in hardware or software. In the case of the laser being a Vertical Cavity Surface Emitting laser (VCSEL), the output signal can be detected by monitoring the surface light emission by means of a beam splitter, or in some embodiments as emission from the bottom surface of the laser. In some embodiments, the system may further comprise a wavelength filter such as an etalon in the signal path.

Abstract: A device has a laser unit, which includes: a top-side p-type DBR region; which is on top of and in direct touch with an active region; which is on top of and in direct touch with a bottom-side n-type Distributed Bragg Reflector (DBR) region; which is on top of a n-type substrate. The laser unit further includes a voltage measurement anode touching or being in proximity to a top surface of the active region; and a voltage measurement cathode touching or being in proximity to a bottom surface of the active region. The voltage between the voltage measurement anode and the voltage measurement cathode is directly measured; and is utilized for determining characteristics of a laser self-mix signal of the laser unit, without having or using a monitor photo-diode.

Abstract: A laser-based device or sensor includes: a first laser transmitter having a first self-mix carrier frequency; a second laser transmitter having a second, different, self-mix carrier frequency; a first monitor photodiode to receive a first optical signal from the first laser transmitter, and to output a first electric signal; a second monitor photodiode to receive a first optical signal from the second laser transmitter, and to output a second electric signal; an electric connection to connect together the first electric signal and the second electric signal, forming a combined electric signal; a single laser receiver to receive the combined electric signal and to generate from it a spectrum that corresponds to both (i) self-mix signal of the first laser transmitter, and (ii) self-mix signal of the second laser transmitter. Alternatively, a single monitor photodiode is used, receiving self-mix signals from multiple laser transmitters, and outputting a single electric signal to a single laser receiver.

Abstract: Device, system, and method of voice-based user authentication utilizing a challenge. A system includes a voice-based user-authentication unit, to authenticate a user based on a voice sample uttered by the user. A voice-related challenge generator operates to generate a voice-related challenge that induces the user to modify one or more vocal properties of the user. A reaction-to-challenge detector operates to detect a user-specific vocal modification in reaction to the voice-related challenge; by using a processor as well as an acoustic microphone, an optical microphone, or a hybrid acoustic-and-optical microphone. The voice-based user-authentication unit utilizes the user-specific vocal modification, that was detected as reaction to the voice-related challenge, as part of a user-authentication process.

Abstract: A system includes a laser microphone or laser-based microphone or optical microphone. The laser microphone includes a laser transmitter to transmit an outgoing laser beam towards a human speaker. The laser transmitter acts also as a self-mix interferometry unit that receives the optical feedback signal reflected from the human speaker, and generates an optical self-mix signal by self-mixing interferometry of the laser beam and the received optical feedback signal. Instead of utilizing a single laser beam, multiple laser beams are used, by operating an array of laser transmitters, or by utilizing a laser beam splitter or a crystal to split laser beams or to diffract or scatter laser beams. Optionally, one or more laser beams may temporally scan a target area.

Abstract: A laser-based device or sensor includes: a first laser transmitter having a first self-mix carrier frequency; a second laser transmitter having a second, different, self-mix carrier frequency; a first monitor photodiode to receive a first optical signal from the first laser transmitter, and to output a first electric signal; a second monitor photodiode to receive a first optical signal from the second laser transmitter, and to output a second electric signal; an electric connection to connect together the first electric signal and the second electric signal, forming a combined electric signal; a single laser receiver to receive the combined electric signal and to generate from it a spectrum that corresponds to both (i) self-mix signal of the first laser transmitter, and (ii) self-mix signal of the second laser transmitter. Alternatively, a single monitor photodiode is used, receiving self-mix signals from multiple laser transmitters, and outputting a single electric signal to a single laser receiver.

Abstract: Optical microphone, laser-based microphone, and laser microphone having reduced-noise components of low-noise components. A laser microphone comprises a laser-diode associated with a low-noise laser driver TX; and a photo-diode associated with a low-noise photo-diode receiver RX. The low-noise laser driver TX supplies a drive current which is a combination of a Direct Current component having a first bandwidth, and an attenuated version of an Alternating Current component having a second, different, bandwidth. Additionally or alternatively, the low-noise photo-diode receiver RX utilizes hardware-based demodulation of the analog signal, and operates to remove a Direct Current component of its output signal prior to digitization.

Abstract: A system includes a laser microphone or laser-based microphone or optical microphone. The laser microphone includes a laser transmitter to transmit an outgoing laser beam towards a face of a human speaker. The laser transmitter acts also as a self-mix interferometry unit that receives the optical feedback signal reflected from the face of the human speaker, and generates an optical self-mix signal by self-mixing interferometry of the laser power and the received optical feedback signal; and a speckles noise reducer to reduce speckles noise and to increase a bandwidth of the optical self-mix signal. The speckles noise reducer optionally includes a vibration unit or displacement unit, to cause vibrations or displacement of one or more mirrors or optics elements of the laser microphone, to thereby reduce speckles noise.

Abstract: Device, system, and method of user authentication utilizing an optical microphone or laser-based microphone. An optical microphone transmits an outgoing optical signal or laser beam towards a face of a human speaker; receives an incoming optical feedback that is reflected back from the face of the human speaker; performs self-mix interferometry that is based on the outgoing optical signal and the incoming reflected optical signal; and generates a user-specific feature or characteristic that uniquely characterizes said human speaker. A user authentication module operates to authenticate the user for performing a privileged or an access-controlled action, based on the user-specific characteristic that was generated, optionally in combination with one or more biometric features or authentication requirements.

Abstract: A laser-based device or sensor includes: a first laser transmitter having a first self-mix carrier frequency; a second laser transmitter having a second, different, self-mix carrier frequency; a first monitor photodiode to receive a first optical signal from the first laser transmitter, and to output a first electric signal; a second monitor photodiode to receive a first optical signal from the second laser transmitter, and to output a second electric signal; an electric connection to connect together the first electric signal and the second electric signal, forming a combined electric signal; a single laser receiver to receive the combined electric signal and to generate from it a spectrum that corresponds to both (i) optical feedback of the first laser transmitter, and (ii) optical feedback of the second laser transmitter. Alternatively, a single monitor photodiode is used, receiving optical signals from multiple laser transmitters, and outputting a single electric signal to a single laser receiver.

Abstract: A laser-based device or sensor includes: a first laser transmitter having a first self-mix carrier frequency; a second laser transmitter having a second, different, self-mix carrier frequency; a first monitor photodiode to receive a first optical signal from the first laser transmitter, and to output a first electric signal; a second monitor photodiode to receive a first optical signal from the second laser transmitter, and to output a second electric signal; an electric connection to connect together the first electric signal and the second electric signal, forming a combined electric signal; a single laser receiver to receive the combined electric signal and to generate from it a spectrum that corresponds to both (i) optical feedback of the first laser transmitter, and (ii) optical feedback of the second laser transmitter. Alternatively, a single monitor photodiode is used, receiving optical signals from multiple laser transmitters, and outputting a single electric signal to a single laser receiver.

Abstract: System and method for operating electric devices based on voice commands, as well as electric devices that can be controlled via voice commands. An electric device comprises an audio sensor to capture audio that contains speech; and a transmitter to transmit the captured audio to a remote server, together with a dictionary identifier that indicates to the remote server which particular dictionary or vocabulary-set to utilize for performing speech recognition on the recorded audio. The remote server performs speech recognition using the relevant dictionary table; and selects a command-code that is transmitted back to the electric device, to trigger an operational modification of the electric device.

Abstract: 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.

Abstract: Laser-based device 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.

Abstract: A system for distinguishing and identifying speech segments originating from speech of one or more relevant speakers in a predefined detection area. The system includes an optical system which outputs optical patterns, each representing audio signals as detected by the optical system in the area within a specific time frame; and a computer processor which receives each of the outputted optical patterns and analyses each respective optical pattern to provide information that enables identification of speech segments thereby, by identifying blank spaces in the optical pattern, which define beginning or ending of each respective speech segment.

Abstract: A system for detection of speech related acoustic signals by using laser based detection that includes a mask configured for being worn over a face part of a speaker covering the speaker's mouth, where the mask includes at least one reflective coating covering at least one area of the mask that reflects collimated electromagnetic signals; and a laser microphone configured for detecting vibrations of the reflective coating area for detection of acoustic signals associated with speech of the speaker by using collimated electromagnetic signals. The mask the reflective coating area thereof allow enhancing detection of vibrations resulting from speech carried out by the speaker wearing said mask.

Abstract: System and method for producing enhanced speech data associated with at least one speaker. The process of producing the enhanced speech data comprises: receiving distant signal data from a distant acoustic sensor; receiving proximate signal data from a proximate acoustic sensor located closer to the speaker than the distant acoustic sensor; receiving optical data originating from an optical unit configured for optically detecting acoustic signals in an area of the speaker and outputting data associated with speech of the speaker; processing the distant and proximate signals data for producing a speech reference and a noise reference; operating an adaptive noise estimation module, which identifies stationary and/or transient noise signal components, using the noise reference; and operating a post filtering module, which uses the optical data, speech reference and identified noise signal components for creating an enhanced speech data.

Abstract: Method and system for tracking fundamental frequencies of pseudo-periodic signals in the presence of noise that include receiving a time-frequency representation of signals measured in a predefined environment; estimating and tracking a fundamental frequency of a respective pseudo-periodic signal at each time frame of the time-frequency representation by tracking detections of harmonious frequencies in the time-frequency representation over time; and outputting each respective estimated fundamental frequency associated with the pseudo-periodic signal of each respective time frame.

Abstract: A system for distinguishing and identifying speech segments originating from speech of one or more relevant speakers in a predefined detection area. The system includes an optical system which outputs optical patterns, each representing audio signals as detected by the optical system in the area within a specific time frame; and a computer processor which receives each of the outputted optical patterns and analyses each respective optical pattern to provide information that enables identification of speech segments thereby, by identifying blank spaces in the optical pattern, which define beginning or ending of each respective speech segment.