The present invention discloses a method for detecting a microstructure of a functionally graded material based on digital acousto-optic holography, including the following steps: excite a sample with an ultrasonic wave; record a light wave; form a single tomographic acousto-optic hologram; perform numerical reconstruction of phase information, and perform global detection. The present invention uses an acoustic-optic modulation device to modulate a laser light source of a laser of a laser device to form two light waves of different frequencies. The two light waves each constitute a Mach-Zehnder interference system to record reflection wave information and transmission wave information of an ultrasound, and are finally combined and recorded in the same hologram to form the single tomographic acousto-optic hologram.

An optical-resolution photoacoustic microscopy (OR-PAM) system for visualizing water content deep in biological tissue uses an all-fiber 1930-nm hybrid optical parametrically-oscillating emitter. The emitter includes a tunable laser source whose output is amplified by a first erbium-doped fiber amplifier (EDFA). The output of the first amplifier is modulated with a Mach-Zehnder amplitude modulator that receives an RF signal with a nanosecond pulse width and a multiple kilohertz repetition rate. A second EDFA further amplifies the signal and passes it to a fiber circulator that in turn delivers it to a 1950/1550 mm fiber wavelength-division-multiplexing coupler WDM. The coupler introduces the signal to a cavity that includes a spool of highly nonlinear fiber and a Thulium-doped fiber amplifier TDFA. From the TDFA the signal reaches a 50/50 fiber coupler that sends part to a second output TDFA and guides part back to the cavity through a port of the WDM.

A defect detection apparatus is provided that can inspect a measurement region of a target object at one time and without inconsistencies arising within the measurement region. A defect detection apparatus 10 includes: a generation unit (signal generator 11 and vibrator 12) for generating an elastic wave in a target object S; an illumination unit (pulsed laser light source 13 and illumination light lens 14) for performing stroboscopic illumination onto a measurement region of a surface of the target object S; and a displacement measurement unit (speckle shearing interferometer 15) for collectively measuring displacements in a normal direction at each point of the measurement region with respect to at least three mutually-different phases of the elastic wave by controlling a phase of the elastic wave and a timing of the stroboscopic illumination. Defects in the measurement region are detected based on the displacements in the normal direction at each point of the measurement region with respect to at least three phases that are obtained by the displacement measurement unit.

A photoacoustic imaging system is disclosed that includes an ergodic relay coupled optically to a light source configured to produce a light pulse and further coupled acoustically to a transducer. The ergodic relay is further configured to direct at least two PA signals to the transducer. Each of the at least two PA signals are produced at different positions within the field of view of the object to be imaged in response to illumination by a single light pulse. The transducer detects each of the at least two PA signals after each of at least two delays that correspond to the position at which each PA signal was produced.

A non-destructive opto-acoustic metrology device detects the presence and location of non-uniformities in a film stack that includes a large number, e.g., 50 or more, transparent layers. A transducer layer at the bottom of the film stack produces an acoustic wave in response to an excitation beam. A probe beam is reflected from the layer interfaces of the film stack and the acoustic wave to produce an interference signal that encodes data in a time domain from destructive and constructive interference as the acoustic wave propagates upward in the film stack. The data may be analyzed across the time domain to determine the presence and location of one or more non-uniformities in the film stack. An acoustic metrology target may be produced with a transducer layer configured to generate an acoustic wave with a desired acoustic profile based on characteristics of the film stack.

There is provided a photoacoustic measurement apparatus including a laser light source unit that has a flash lamp for emitting excitation light and a laser rod for emitting laser light in response to incidence of the excitation light, an excitation light source power supply unit that has a capacitor bank for supplying a voltage to the flash lamp, an IGBT for controlling an output of the voltage charged in the capacitor bank to the flash lamp, a discharge control circuit for generating a driving pulse for driving the IGBT, and a pulse width limiting circuit for limiting a pulse width of the driving pulse output from the discharge control circuit, the pulse width limiting circuit being formed of a passive element, and a photoacoustic wave detection unit that detects photoacoustic waves generated inside a subject by emission of light emitted from the laser light source unit to the subject.

A first signal is generated with a first light detector in response to an ultrasound signal encountering a first measurement beam. A second signal is generated with a second light detector in response to the ultrasound signal encountering a second measurement beam. The second measurement beam propagates through the sample and the first measurement beam propagates outside the sample.

An elastic wave receiving apparatus includes: a probe that receives an elastic wave generated from a subject; a plate-like compression plate that supports the subject and whose surface is scanned by the probe; a motor for driving the probe; a controller that supplies a drive signal to the motor so that the probe moves to a predetermined target position on the compression plate; and a load estimating unit that preliminarily acquires and stores a physical value corresponding to a load generated at the time of scanning the compression plate by the probe. The controller corrects the drive signal so that the probe moves to the target position regardless of the load by using the physical value stored in the load estimating unit.

A measuring device for non-mechanical-contact measurement of a layer, the measuring device including a light source operative to generate a pulse adapted to interact with the layer so as to generate a thermal wave in a gas medium present adjacent the layer. The thermal wave causes an acoustic signal to be generated. The measuring device further includes a detector adapted to detect a first signal responsive to the acoustic signal, the detector not being in mechanical contact with the layer. The first signal is representative of the measured layer.

A photoacoustic apparatus comprises a light source; an acoustic wave receiver receives an acoustic wave and converts into an electric signal; a first acquisition unit acquires a first absorption coefficient distribution inside the object using a first method; a second acquisition unit acquires a second absorption coefficient distribution inside the object using a second method; a third acquisition unit calculates the distribution of functional information on the interior of the object; and an image generation unit generates an image by masking the distribution of the functional information based on the second absorption coefficient distribution, wherein the second method is a method that can implement higher visibility than the first method when the absorption coefficient distribution is imaged.