A fiber optic sensor for detecting an excitation in proximity to a fiber optic assembly, the excitation inducing a modulation of the phase of an optical signal propagating in the fiber optic assembly, the sensor comprises: a laser assembly emitting at least one laser beam; a fiber optic assembly; an optical system configured to: inject at least one portion of the laser beam; generate at least one laser signal beam issued from the laser beam injected into and propagated in the fiber assembly; generate at least one reference beam from the laser beam or the signal beam; produce at least one interference zone corresponding to the interference between a portion of the reference beam and a portion of the interference signal beam corresponding to the interference between a portion of the reference beam and a portion of the signal beam; a digital holography assembly comprising: a liquid-crystal spatial light modulator; a video camera configured to receive the interference zone and to transcribe it electrically to the liquid-crystal spatial light modulator in order to create thereon a phase hologram corresponding thereto; at least one optical detector configured to detect an output optical signal beam.

A technique facilitates the use and application of a distributed vibration sensing system in, for example, a well application. The technique enables selection of a desired gauge length to achieve an optimum trade-off between the spatial resolution of a distributed vibration sensing/distributed acoustic sensing system and signal-to-noise ratio. The optimum gauge length can vary according to specific factors, e.g. depth within a well, and the present technique can be used to account for such factors in selecting an optimal gauge length which facilitates accurate collection of data on dynamic strain.

An object information obtaining device includes a light source which emits light, an acoustic wave detecting unit which detects a photoacoustic wave generated by irradiation of an object with the light, and outputs an electric signal in response to detection of the photoacoustic wave, and a processing unit configured to perform two or more types of processing to photoacoustic signal data based on the electric signal to obtain object information corresponding to each of the two or more types of processing, and to display on a display unit the object information corresponding to at least one processing selected by a user out of the two or more types of processing.

An object information obtaining device includes a light source which emits light, an acoustic wave detecting unit which detects a photoacoustic wave generated by irradiation of an object with the light, and outputs an electric signal in response to detection of the photoacoustic wave, and a processing unit configured to perform two or more types of processing to photoacoustic signal data based on the electric signal to obtain object information corresponding to each of the two or more types of processing, and to display on a display unit the object information corresponding to at least one processing selected by a user out of the two or more types of processing.

System include an ultrasonic transducer configured to couple to a nondestructive testing (NDT) sample and configured to produce and direct an ultrasonic probe wave at a selected frequency into a subsurface region of the NDT sample, a 3D laser scanning vibrometer configured to direct a detection beam in a scan area on a surface of the NDT sample and to receive a return beam from the scan area, and to detect, based on the return beam, a 3D motion of the surface across a wideband frequency range, and a processor, and a memory configured with instructions that, when executed by the processor, cause the processor to produce sub-surface image data of the NDT sample at multiple harmonics of the selected frequency in the wideband frequency range based on the detected 3D surface motion, wherein the sub-surface image data describes a nonlinear defect response produced in the NDT sample by interaction of the ultrasonic probe wave with the subsurface region.

The present invention relates to a fiber optic sensor, a method of manufacturing the same, and a vibroscope using the same. A fiber optic sensor according to an embodiment of the present invention includes: an optical cable; an optical fiber taken out of the optical cable and provided with a fiber Bragg grating (FBG); a mold housing as a case into or to which the optical cable and the optical fiber are partially inserted and fixed, the mold housing including an optical cable accommodation groove to accommodate the optical cable, an optical fiber accommodation hole extending from the optical cable accommodation groove to accommodate the optical fiber, and a coating agent introduction hole communicated with the optical fiber accommodation hole so as to allow fluid to flow therebetween from an outer side of the mold housing so that a liquid-type coating agent permeates via the optical fiber accommodation hole; and a coating layer filling the optical fiber accommodation hole and the coating agent introduction hole and formed on an outer circumference of the optical fiber including the FBG and a surface of the mold housing.

A system includes at least one earpiece wherein each earpiece comprises an earpiece housing, a light source operatively connected to each earpiece housing and configured to transmit substantially coherent light toward an outer surface of a user's body, a light receiver operatively connected to the earpiece housing proximate to the light source and configured to receive reflected light from the outer surface of the user's body, and one or more processors disposed within the earpiece housing and operatively connected to the light source and light receiver, wherein one or more processors is configured to determine bone vibration measurements from the reflected light. A method of determining bone vibrations includes providing at least one earpiece, transmitting substantially coherent light toward an outer surface of a user's body using the earpiece, receiving reflected light from the outer surface of the user's body using the earpiece, and determining bone vibration measurements using the earpiece.

An acoustic system and method is disclosed for providing spatial and temporal classification of a range of different types of sound producing targets in a geographical area. The system includes an optical signal transmitter arrangement for repeatedly transmitting, at multiple instants, interrogating optical signals into each of one or more optical fibres distributed across the geographical area and forming at least part of an installed fibre-optic communications network. An optical signal detector arrangement receives, during an observation period following each of the multiple instants, returning optical signals scattered in a distributed manner over distance along the one or more of optical fibres. A processing unit demodulates acoustic data from the optical signals, processes the acoustic data and classifies it in accordance with the target classes or types to generate a plurality of datasets including classification, temporal and location-related data, and a storage unit stores the datasets in parallel with raw acoustic or optical data which is time and location stamped so that it can be retrieved for further processing.

Remote recovery of acoustic signals from passive sources is provided. Wideband radars, such as ultra-wideband (UWB) radars can detect minute surface displacements for vibrometry applications. Embodiments described herein remotely sense sound and recover acoustic signals from vibrating sources using radars. Early research in this domain only demonstrated single sound source recovery using narrowband millimeter wave radars in direct line-of-sight scenarios. Instead, by using wideband radars (e.g., X band UWB radars), multiple sources separated in ranges are observed and their signals isolated and recovered. Additionally, the see-through ability of microwave signals is leveraged to extend this technology to surveillance of targets obstructed by barriers. Blind surveillance is achieved by reconstructing audio from a passive object which is merely in proximity of the sound source using clever radar and audio processing techniques.

Remote recovery of acoustic signals from passive sources is provided. Wideband radars, such as ultra-wideband (UWB) radars can detect minute surface displacements for vibrometry applications. Embodiments described herein remotely sense sound and recover acoustic signals from vibrating sources using radars. Early research in this domain only demonstrated single sound source recovery using narrowband millimeter wave radars in direct line-of-sight scenarios. Instead, by using wideband radars (e.g., X band UWB radars), multiple sources separated in ranges are observed and their signals isolated and recovered. Additionally, the see-through ability of microwave signals is leveraged to extend this technology to surveillance of targets obstructed by barriers. Blind surveillance is achieved by reconstructing audio from a passive object which is merely in proximity of the sound source using clever radar and audio processing techniques.