156results about "Optical signal transducers" patented technology

An apparatus is described herein related to detecting and processing silent speech. The apparatus comprises a head-mountable device and at least one ear-mountable device, wherein the ear-mountable devices are configured to selectively pick up both head-internal and head-externals sounds, thus enabling silent speech to be detectable and wherein the head-mountable device comprises an eye tracking unit capable of determining a gaze dwell of a user of the device, thus enabling silent speech commands to be directed at objects subject to a gaze dwell, or enabling speech or audio originating from an interlocutor who is subject to a gaze dwell to be selectively enhanced. Methods are described herein relate to the application of semantic intent derived from a silent speech to real-word objects which are subject to a gaze dwell by a user.

An optical displacement sensor comprises a reflective surface and one or more diffraction gratings which, together with the reflective surface, each define a respective interferometric arrangement. The reflective surface is moveable relative to the diffraction grating(s) or vice versa. Light from a light source propagates via the interferometric arrangement(s) to produce an interference pattern at a respective set of photo detectors. Each interference pattern depends on the separation between the reflective surface and the respective grating. A collimating optical arrangement at least partially collimates the light between the light source and the diffraction grating(s). For the or each interferometric arrangement, when the reflective surface or the diffraction grating is in a zero-displacement position, the optical path length L of the light propagating between the diffraction grating and the reflective surface satisfies the relationship:L=Tz⁢n2,to within 20% ofTz2,where n is an integer; where Tz is the Talbot length, defined by:Tz=λ1-1-λ2p2,where λ is the wavelength of the light, and where p is the grating period of the respective diffraction grating.

This invention unveils an optical microphone utilizing diamond cantilevers and its associated acoustic sensing system. The core component is a diamond cantilever, featuring a diamond diaphragm with a centrally located U-shaped groove. The manufacturing process involves several key steps: initially preparing the diamond diaphragm using silicon in a chemical vapor deposition setup, where methane and hydrogen are reacted under specific temperature and pressure conditions to form a diamond polycrystalline film on the silicon. This film is then separated from the substrate to create the diaphragm. Subsequently, a U-shaped groove is crafted on the diaphragm by applying a dry etching template and etching, resulting in the formation of the diamond cantilever, with a thickness ranging from 10 to 100 μm. This method establishes a novel approach to creating sensitive and durable optical microphones.

An audio system including an optical microphone and an audio controller. The optical microphone includes a light source and a detector. In some embodiments, the light source illuminates skin of a user. Alternatively the optical microphone also includes a membrane, and the light source illuminates a portion of the membrane. Sounds from a local area cause vibrations in the skin (or vibrations in the membrane). The detector may be in an interferometric configuration or a non-interferometric configuration with the light source. The audio controller monitors the vibrations of the skin (or membrane) using signal output from the detector, and measures the sounds using the monitored vibrations.

An optical microphone assembly including a substrate having a first and second substrate portions with the first substrate portion being thinner than the second substrate portion, an interferometic arrangement including a membrane and at least one optical element including a surface of the first substrate portion and / or is disposed on a surface of the first substrate portion, and the at least one optical element does not include a diffractive optical element formed as a plurality of holes through the first substrate portion. The optical microphone assembly further includes a light source arranged to provide light to the interferometric arrangement such that a first portion of the light propagates along a first optical path via the interferometric arrangement and a second portion of the light propagates along a second different optical path via the interferometric arrangement, thereby giving rise to an optical path difference between the first and second optical paths which depends on a distance between the membrane and the optical element, and with at least one of the first and second paths passing through the first substrate portion, and at least one photo detector arranged to detect at least part of an interference pattern generated by said first and second portions of light dependent on the optical path difference.

A noise suppression apparatus according to the present disclosure includes at least one memory configured to store instructions, and at least one processor configured, by executing the instructions, to input a plurality of noise superimposed signals that are acquired by distributed acoustic sensing (DAS) using an optical fiber cable and on which noise is superimposed, extract a common feature of the plurality of input noise superimposed signals as a noise suppression signal in which noise is suppressed, and output the extracted noise suppression signal.

The invention provides an optical microphone and a sound wave detection method. The optical microphone includes: an MEMS structural member configured to generate a vibration displacement in response to a sound wave; the laser device is configured to emit laser to the MEMS structural member and receive reflected light of the MEMS structural member, so that self-mixing interference is formed in the MEMS structural member, and the emergent light intensity of the laser device linearly changes along with the vibration displacement; and the photoelectric detector is configured to convert the emergent light intensity into a current signal reflecting the sound wave. Linear conversion between sound wave vibration and an electric signal is realized by regulating and controlling a feedback intensity factor, and a complex demodulation process is omitted; by adopting the compact integration or split type optical path design of the MEMS structure, the laser and the detector, the system has the advantages of high sensitivity, high environmental adaptability, easiness in mass production and the like.

An optical displacement sensor comprises a reflective surface and one or more diffraction gratings which, together with the reflective surface, each define a respective interferometric arrangement. The reflective surface is moveable relative to the diffraction grating(s) or vice versa. Light from a light source propagates via the interferometric arrangement(s) to produce an interference pattern at a respective set of photo detectors. Each interference pattern depends on the separation between the reflective surface and the respective grating. A collimating optical arrangement at least partially collimates the light between the light source and the diffraction grating(s). For the or each interferometric arrangement, when the reflective surface or the diffraction grating is in a zero-displacement position, the optical path length L of the light propagating between the diffraction grating and the reflective surface satisfies the relationship:L=Tz⁢n2,to within 20% ofTz2, where n is an integer; where Tz is the Talbot length, defined by:Tz=λ1-1-λ2p2,where λ is the wavelength of the light, and where p is the grating period of the respective diffraction grating.

The present application provides a sound capture method applied to a microphone. The microphone comprises a laser self-mixing device and a diaphragm device, the diaphragm device comprises a membrane configured to respond to sound vibration, and the laser self-mixing device and the diaphragm device are separately configured to detect the vibration of the membrane. In the method, a first voltage signal is obtained using the laser self-mixing device, and a second voltage signal is simultaneously obtained using the diaphragm device. If the first voltage signal is equal to or less than a preset threshold, the first voltage signal is converted into an audio signal, or if the first voltage signal is greater than a preset threshold, the second voltage signal is converted into an audio signal. According to the method of the present application, the audio signal may be collected in two different manners, so that the switching between the two signals is realized using a preset threshold, and the more consistent signal is selected and converted into an audio signal. This can ensure the quality of the audio signal. The present application further relates to a microphone and an electronic device.

A vehicle is provided, comprising at least one optical sensor arranged on an exterior surface thereof, as well as a control unit which is in signal communication with the optical sensor and which is configured to process data acquired by the optical sensor, wherein the optical sensor is arranged and configured to optically record acoustic signals generated in the exterior surface of the vehicle and to transmit them to the control unit, wherein the control unit is configured to determine a voice command from the optically recorded acoustic signal.Furthermore, a method for detecting an acoustic signal outside the vehicle is provided by means of an optical sensor serving as a visual microphone, which is arranged on an exterior of the vehicle, wherein only acoustic signals which are recognized as a voice command during the processing of the acoustic signals are further processed in such a way that the voice command is executed by the vehicle.

The invention provides an opto-acoustic signal quality enhancement method and system adopting multi-laser cooperative sound production, and the method comprises the steps: collecting an external sound signal, and converting the collected external sound signal into an electric signal; performing band-pass filtering of different frequencies on the electric signals to obtain filtered electric signals; modulating according to the characteristics of the filtered electric signals to obtain laser control information; and controlling the laser to output laser signals according to the laser control information, and irradiating the plurality of laser signals to the ear position. Two or more acoustic laser beams are adopted to irradiate the ears, and acoustic signals with higher quality are excited in the ears.

The invention relates to the technical field of optical fiber sensing, in particular to a temperature-insensitive F-P interference type optical fiber microphone probe structure, which comprises a vibrating diaphragm for sensing sound vibration, a shell, a sleeve and an optical fiber, and is characterized in that the shell structure of the shell is made of an all-quartz material; the casing pipe comprises an inner casing pipe, a middle casing pipe and an outer casing pipe, and the inner casing pipe is used for placing the optical fiber without the coating layer; the middle sleeve is used for placing the inner sleeve, and the middle sleeve is clamped through the first five-dimensional adjusting frame; the outer sleeve is used for placing the middle sleeve, and the outer sleeve is clamped through the second five-dimensional adjusting frame; the vibrating diaphragm is connected with the outer sleeve, the size of the corresponding diameter of the vibrating diaphragm is determined based on the outer diameter of the middle sleeve, the distance between the vibrating diaphragm and the end face of the optical fiber is determined by adjusting the first five-dimensional adjusting frame and the second five-dimensional adjusting frame, and the inner sleeve and the outer sleeve are welded under the condition that the distance conforms to the preset distance, so that the temperature-insensitive F-P interference type optical fiber microphone probe is obtained. By applying the probe structure, the influence of temperature can be reduced to the minimum.

A method and system for distributed acoustic sensing in a city or metropolitan area or the like that includes a dedicated, established fiber optic communication network, including a data center, is provided. [Solution] The method and system include the steps of: (a) selecting an optical fiber cable plant having a route extending across a selected geographic area, including a bundle of optical fibers and forming part of an optical fiber communications network; (b) determining characteristics associated with the optical fibers associated with the plant and / or the selected optical fibers; (c) transmitting emitted light within the optical fiber; (d) receiving reflected light backscattered along the optical fiber; and (e) generating an alarm signal representative of an acoustic event based on the reflected light and the determined characteristics, and may be useful for detecting acoustic events near or within the selected geographic area.

An acoustic output of therapeutic devices used in shock wave therapy can be obtained by measuring the pressure waves radiated from the pressure wave transducer in water. Since the pressure waves used in shock wave therapy generate severe bubbles in water, measuring the surface vibrations of the pressure wave transducer using the laser Doppler method includes significant noise caused by the bubbles. This invention utilizes a filter generated to eliminate the noise in the vibration signals measured by the laser Doppler method, which is caused by the bubbles. The filter is generated by comparing the vibration signals measured in degassed distilled water with the reference signals measured in air at the minimum output setting of the shock wave generation device. Using the filter, it is possible to estimate the vibration signals of the pressure wave transducer generated underwater under the set conditions of the specific shock wave generating device.

A microphone 1 includes a light source 11 that outputs an optical signal, an optical coupler 12 that demultiplexes and multiplexes the optical signal, a transmission path 13 including an optical fiber 130 that transmits a demultiplexed optical signal demultiplexed by the optical coupler 12 to the optical coupler 12 in mutually opposite directions, a sensor part 14 that is connected to the transmission path 13 and returns the demultiplexed optical signal to be transmitted by the transmission path 13 to the transmission path 13 via a space part 40, and a light receiving element 15 that receives a multiplexed optical signal multiplexed by the optical coupler 12.

A laser-induced plasma (LIP) sound generator comprising: a laser beam and a first beam splitter configured to split the laser into a plurality of sub-laser beams such that each sub-laser beam creates a LIP at a respective focal point, wherein each focal point lies within an imaginary sphere having a radius that is less than half of a desired sound wavelength such that acoustic fields of the LIPs add together as if from a single point source.

Aspects of the present disclosure describe DFOS / DAS systems, methods, and structures that employ active microphones to enhance DAS operational capabilities by using active circuitry to amplify acoustic signals, including voice. The circuitry includes a microphone that collects acoustic signals derived from audio signals in the environment, and a speaker or vibration device driven by an amplifier. The circuitry can be clipped to the fiber and directly contacted via the speaker or vibration device. A microcontroller can be advantageously employed to control the circuitry to reduce power consumption by locally detecting activity and enabling the speaker only when needed. The microcontroller can also transmit other information, such as battery status, in vibration code to the DFOS interrogator.

An embodiment of this application provides a laser microphone, including a diaphragm, a laser device, a control circuit, a self-mixing signal obtaining apparatus, and a signal processing circuit. The laser device is configured to emit light to the diaphragm and receive a feedback light signal from the diaphragm, and the feedback light signal interferes with laser in a resonant cavity of the laser device to obtain a self-mixing light signal. A distance between the laser device and the diaphragm ranges from 30 to 300 µm. The control circuit is connected to the laser device, and is configured to drive and control the laser device to emit light. The self-mixing signal obtaining apparatus is connected to the laser device, and is configured to obtain a target voltage signal related to the self-mixing light signal. The signal processing circuit is connected to the self-mixing signal obtaining apparatus, and is configured to receive the target voltage signal output by the self-mixing signal obtaining apparatus and process the target voltage signal into an audio voltage signal. The laser microphone has a high signal-to-noise ratio, such that a voice recognition rate and an awakening rate can be increased, and long-distance sound pickup effect is improved. An embodiment of this application further provides a terminal including the laser microphone.

A microphone (1) is provided with: a light source (11) that outputs an optical signal; an optical coupler (12) for demultiplexing and multiplexing the optical signal; a transmission path (13) that includes an optical fiber (130) that transmits the demultiplexed optical signals demultiplexed by the optical coupler (12) to the optical coupler (12) in mutually opposite directions; a sensor unit (14) that is connected to the transmission path (13) and returns the demultiplexed optical signal transmitted by the transmission path (13) to the transmission path (13) via the space unit (40); and a light receiving element (15) that receives a multiplexed optical signal multiplexed by the optical coupler (12).

The invention provides an optical microphone demodulation method and system based on a digital optical comb, and the method comprises the steps: carrying out the inverse fast Fourier transform of a data sequence of a constant-amplitude pseudo-random phase relation, and converting the data sequence into an analog signal; performing light splitting on the optical signal to obtain two paths of optical signals; one path of optical signal is used as a reference optical signal, and the other path of optical signal is subjected to optical frequency comb modulation through an analog signal to obtain a measurement optical signal; enabling the target sound wave to act on the measurement optical signal, causing the spectral characteristic offset of the measurement optical signal through an acoustic-optical coupling effect, and obtaining an offset optical signal; performing coherent detection on the reference optical signal and the offset optical signal to obtain a detection signal; and sampling the detection signal, and analyzing the target sound wave based on the sampled data. According to the invention, tiny optical frequency change caused by sound signals can be captured, and high-precision application scene requirements can be met; tiny optical frequency deviation caused by extremely weak sound can be clearly distinguished, and high-sensitivity and high-resolution detection of weak sound signals is achieved.

To further suppress noise in a noise superimposition signal.SOLUTION: A noise suppression device according to the present disclosure includes a common feature extractor that inputs a plurality of noise-superimposed signals acquired by distributed acoustic sensing (DAS) using an optical fiber cable and having noise superimposed thereon, extracts common features of the input plurality of noise-superimposed signals as a noise suppression signal in which noise has been suppressed, and outputs the extracted noise suppression signal.SELECTED DRAWING: Figure 8

A distributed forwarding sensing system and method for multi-event localization and high-fidelity acoustic waveform reconstruction in which the method includes modeling a bi-directional distributed forwarding sensing scheme as an equivalent dual-element sensor array (SA2), where an event location (z) along a fiber is mapped to a direction-of-arrival (DOA) angle (α). Signals from first and second receivers are transformed into the time-frequency domain. Generalized Cross-Correlation with Phase Transform (GCC-PHAT) is used to accurately localize multiple simultaneous events by estimating a time shift (Δτ). An adaptive beamforming technique, such as a Generalized Sidelobe Canceller (GSC), is then steered toward the desired event location to enhance the acoustic signal and mitigate noise and interference from other locations along the fiber, resulting in a high-fidelity reconstructed acoustic waveform suitable for machine learning classification.

Examples relate to a method (10) for detecting an acoustic signal (Sig) on ​​a vehicle (21), the method (10) comprising: using (11) a laser device (Lid', Lid'') of the vehicle for a laser microphone system to detect an acoustic vibration on a predetermined surface (21a, 41) of the vehicle (21); aligning (12) the laser device (Lid', Lid'') of the vehicle (21) onto the predetermined surface; sending (13) laser beams (L2) onto the predetermined surface by means of the aligned laser device (Lid', Lid''); and receiving (14) laser beams reflected from the predetermined surface by means of the aligned laser device (Lid', Lid'') in order to calculate the acoustic signal (Sig) from the reflected laser beams with the superimposed acoustic vibration.

The present application discloses an optical microphone, comprising: a piezoelectric transducer for receiving sound energy, driving the piezoelectric composite vibration layer of the piezoelectric transducer to vibrate, and converting it into a piezoelectric signal; a control circuit for receiving the piezoelectric signal and sending a start signal when the piezoelectric signal is greater than a set threshold; a light source for receiving the start signal and emitting a light signal; a reflective layer for receiving and reflecting the light signal; and a light detector for receiving the reflected light signal. The optical microphone provided by the present application measures the vibration of the piezoelectric composite vibration layer by an optical method, thereby obtaining an optical microphone with low standby power consumption and high signal-to-noise ratio.

An optical displacement sensor (2) comprises a reflective surface (4) and one or more diffraction gratings (6) which, together with the reflective surface, each define a respective interferometric arrangement. The reflective surface (4) is moveable relative to the diffraction grating(s) (6) or vice versa. Light from a light source (8) propagates via the interferometric arrangement(s) to produce an interference pattern at a respective set of photo detectors (10). Each interference pattern depends on the separation between the reflective surface (4) and the respective grating (6). A collimating optical arrangement (14) at least partially collimates the light between the light source (8) and the diffraction grating(s) (6). For the or each interferometric arrangement, when the reflective surface (4) or the diffraction grating (6) is in a zero-displacement position, the optical path length L of the light propagating between the diffraction grating (6) and the reflective surface (4) satisfies the relationship: to within 20% of j, where n is an integer; where Tz is the Talbot length, defined by: where λ is the wavelength of the light, and where p is the grating period of the respective diffraction grating (6). Alternatively, L may satisfy: to within 20% of p where m is an odd integer. Additionally or alternatively, the optical displacement sensor (34; 112) may comprise two or more diffraction gratings (44, 46; 116) and may be configured to provide a respective separate light beam (62, 64; 132) to each grating (44, 46; 116) using a beam-separating arrangement (48; 126) or plural light source elements.

To recognize an event without performing model learning using an observation signal acquired by optical fiber sensing.SOLUTION: An event recognition device (20) comprises: an acquisition section (21) that acquires an observation signal indicating sound or vibration that occurs at a point along an optical fiber and is detected by optical fiber sensing and also acquires a noise signal indicating optical noise; a derivation section (22) that uses statistical information (23) on a sound signal or a vibration signal acquired by a sound sensor or a vibration sensor to derive a posterior probability that an event occurs at a point along the optical fiber from the observation signal and derive a posterior probability that the event occurs at a point along the optical fiber from the noise signal; and a comparison section (24) that compares the posterior probability derived from the observation signal with the posterior probability derived from the noise signal, derives, from a result of the comparison, the posterior probability that the event occurs at a point along the optical fiber, and outputs a result of the derivation.SELECTED DRAWING: Figure 8

In order to facilitate the disposition of multiple noise measuring points in a distributed manner, this underwater noise monitoring device is provide with: a processing unit in which, by using data which was acquired using optical fibers installed underwater or on a bottom of water and which indicates noise or vibration at the position of each of the optical fibers, a statistical value of the amount of noise or vibration is derived at the time and the place when / where the data was acquired; and an output unit that outputs the statistical value.

The invention relates to a method for producing a target break line (3) with a defined tear resistance in an airbag cover (2). The target break line (3) is produced using a removal method, in which sound waves are generated along a line (L) at the respective machining location using a tool. The creation of a predefined tear resistance along the target break line (3) is controlled in that an optical control signal for controlling the removal is formed which is influenced by the sound waves.

A sound measuring device includes: a light source that emits a laser beam; a frame including at least one reflective surface that faces a predetermined space through which sound travels, and transversely surrounds the predetermined space with respect to a sound propagation direction; and a light receiver that receives the laser beam multiply reflected by the at least one reflective surface. The at least one reflective surface is disposed to multiply reflect and cross the laser beam in the predetermined space as viewed from the sound propagation direction.

The optical displacement sensor (2) includes a reflecting surface (4) and one or more diffraction gratings (6) that, together with the reflecting surface, each define an interference arrangement. The reflecting surface (4) is movable relative to the diffraction gratings (6), or vice versa. Light from a light source (8) propagates through the interference arrangement and produces an interference pattern at each set of photodetectors (10). Each interference pattern depends on the separation between the reflecting surface (4) and each grating (6). A collimating optical arrangement (14) at least partially collimates the light between the light source (8) and the diffraction grating (6). For the or each interference arrangement, when the reflecting surface (4) or diffraction grating (6) is in a zero-displacement position, the optical path length L of light propagating between the diffraction grating (6) and the reflecting surface (4) satisfies the following relationship to within 20% of j, where n is an integer, and Tz is the Talbot length defined as follows: λ is the wavelength of the light, and p is the grating period of each diffraction grating (6): Alternatively, L is within 20% of p, where m is an odd integer. Additionally or alternatively, the optical displacement sensor (34, 112) may include two or more diffraction gratings (44, 46, 116) and may be configured to provide each separate light beam (62, 64, 132) to each grating (44, 46, 116) using a beam separation arrangement (48, 126) or multiple light source elements.