A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

A method for visualizing details in a sample including directing an excitation beam to an excitation location below a surface of the sample, to generate signals in the sample; directing an interrogation beam toward the excitation location of the sample; directing a signal enhancement beam to the sample, to raise a temperature of a portion of the sample by 5 Kelvin or less, compared to a temperature of the portion of the sample in absence of the signal enhancement beam; detecting a portion of the interrogation beam returning from the sample that is indicative of the generated signals.

An inspection method is provided. The inspection method includes inspecting a plurality of first observation sites by detecting ultrasonic signals emitted from the plurality of first observation sites, inspecting a plurality of second observation sites by detecting ultrasonic signals emitted from the plurality of second observation sites; and inspecting a target structure by detecting an ultrasonic signal emitted from the target structure, where the target structure includes a structure of interest, and wherein the plurality of first observation sites are intermediate results of forming the target structure, respectively, and the plurality of second observation sites are structures modified from the target structure.

A device for the contactless determination of at least one property of a metal product during the metallurgical production of the metal product comprises a housing and at least one measuring device comprising a transmitting unit and a receiving unit. An electromagnetic field is generated by the transmitting unit and directed onto the metal product, thereby inducing a physical interaction in the material of the metal product, and a remaining and/or resulting part of this physical interaction is subsequently received by the receiving unit. At least one component of the measuring device comprising the transmitting unit and/or the receiving unit can be moved relative to the housing or the metal product moving therein, in order to thereby set or selectively change a predetermined distance to the metal product for the transmitting unit and/or the receiving unit.

A photoacoustic probe includes a light source that emits light, an acoustic sensor that is arranged such that an axial direction is in parallel to a depth direction of an object to be measured and detects a sound produced from the object to be measured, a propagation member that propagates the light from the light source to the object to be measured, and propagates the sound produced from the object to be measured by emission of the light from the light source to the acoustic sensor, a reflection member that is provided within the propagation member, reflects the light from the light source, and emits reflected light to the object to be measured in the axial direction of the acoustic sensor, and a sweep mechanism capable of changing a position at which the light from the light source enters the reflection member.

A method and apparatus for detecting a photoacoustic light signal to prevent unauthorized voice commands for a microphone-controllable device are provided. The method includes receiving, by a processor, a signal, detecting, by the processor, that the signal is a photoacoustic signal generated by a thermal expansion and contraction of an object caused by at least one lightwave applied to the object, and activating, by the processor, a counter-measure to prevent the photoacoustic signal from reaching a microphone of a microphone-controllable device in response to detecting the photoacoustic signal.

Methods, devices, and systems for detecting one or more discontinuities of a structure may include a laser emitter configured to generate and direct an ultrasonic signal into a structure and a receiver comprising an optical microphone. The optical microphone may comprise an array of optical microphones configured in a complementary manner to the emitter.

A microscale photoacoustic sensor uses the detection of ultrasound waves generated by a sample in response to incident light absorption to perform photoacoustic spectroscopy, imaging, and microscopy. The microscale photoacoustic sensor, including components to excite a sample and detect ultrasound waves, may be integrated onto a single chip. The microscale photoacoustic sensor may excite a sample using a metasurface collimator. The metasurface collimator includes an array of diffraction grooves to collimate an excitation beam uniformly out of the plane of the sensor to create a wide and homogeneous beam spot. The microscale photoacoustic sensor may detect ultrasound waves using an optical photoacoustic transducer. The optical photoacoustic transducer includes a resonator on a mechanical membrane to detect ultrasound waves with high sensitivity. The microscale photoacoustic sensor may be used in applications such as deep-tissue neural imaging or microfluidic biological screening.

A system and method for authentication of objects, which includes directing a laser beam onto a surface of an object to induce a thermoelastic excitation in bulk material of the object without altering the surface of the object, wherein the laser beam is pulsed. A surface ultrasonic wave at the surface of the object caused by the thermoelastic excitation is detected using a detector. A detection signal is generated using the detected surface ultrasonic wave. Digital data is generated using the detection signal. Authenticity of the object is determined by comparing the digital data and reference data stored in a database.

A method for inspecting fibered optical communication paths. The method includes causing an acoustic signal generator near a fibered optical path to produce an acoustic signal; causing a laser to emit at least one optical pulse into the at least one fibered optical path at an emission time; detecting a plurality of reflected optical signals, each reflected optical signal having an arrival time; determining a distance traveled by each of the plurality of reflected optical signals, in which the distance traveled by a given reflected signal is determined at least in part on the arrival time of the given reflected signal and the emission time of the at least one optical pulse; and detecting for at least one distance traveled by the given reflected signal, a phase oscillation induced at least in part by the acoustic signal.