Vocalzoom Systems Ltd.

Intel Corporation

Vixar, Inc.

Tal Fishman

Tal Bakish

Alexander Blumkin

Amir Ganani

Klein L Johnson

Gil Levy

Reuven Elhamias

Eytan Keydar

Guy Ofek

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.

Self-mix module utilizing filters

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.

Laser-based devices utilizing temperature modulation for improved self-mix sensing

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.

Laser-based devices utilizing improved self-mix sensing

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.

Laser-based devices utilizing multiple laser beams

Laser-based apparatus utilizing multiple laser beams

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.

Low-noise driver and low-noise receiver for self-mix module

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. The speckles noise reducer optionally includes a dynamic laser modulation modifier unit, to dynamically modify modulation properties of a laser modulator associated with the laser transmitter; optionally by modifying an operating temperature of the laser. Optionally, modifications are performed based on a timing scheme, or based on a pseudo-random scheme, or based on a calibration process that selects an advantageous modification scheme. Optionally, the system detects self-mix signal magnitude or bandwidth or quality, and activates the speckles noise reduction mechanism if the self-mix signal appears to be weak or low-quality.

Laser microphone utilizing speckles noise reduction

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.

Laser-based device utilizing multiple laser beams

Laser-based system utilizing multiple laser beams

An optical modulator consists of an electrical input for receiving an electrical control signal, an optical output for outputting an optical signal, and at least two optical cavities coupled together according to a set of coupling parameters. The electrical control signal frequency is in a narrow frequency band, and the coupling parameters are selected to match the modulator frequency band of operation.

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Haifa, Israel

Tal Fishman