An apparatus has an additive manufacturing system configured to deposit material in layers to form a three-dimensional object on a surface, an energy source positioned adjacent the object positioned such that energy from the source reaches the object, a detector to receive energy reflected from the object, and a controller configured to activate the energy source and receive signals from the detector as each layer is deposited. A method of monitoring an additive manufacturing process includes depositing material in a layer on a surface to form a three-dimensional object, activating an energy source located adjacent the surface, detecting reflections of the energy from the object, analyzing the reflections to determine an integrity of the object, and providing a notification when the integrity of the object does not meet a threshold.

A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

A method comprises a) radiating at least one measurement light pulse having a pulse duration and intensity onto a measurement area of the inhomogeneous sample; b) detecting at least one pressure transient at the measurement area; and c) calculating a value for the energy density absorbed by the sample during the pulse duration from a curve of the at least one pressure transient at the start and at the end of the at least one measurement light pulse. The method further includes: repeating steps a) to c) for different angles of incidence of the measurement light; modelling the inhomogeneous sample as a stack of layers, each layer being assigned at least a layer thickness and an absorption coefficient, at least one absorption coefficient of a layer being a fitting parameter; and performing a fitting procedure for the fitting parameters; outputting the fitted fitting parameters.

Provided is an apparatus configured to analyze a component of an object, the apparatus including a signal detection sensor including a light source configured to emit light to the object, a detector configured to detect a signal of light scattered or reflected from the object, an ultrasonic generator configured to transmit an ultrasonic wave toward the object at irregular ultrasonic transmission time intervals to modulate a frequency of the light emitted to the object, and a controller configured to control the ultrasonic transmission time intervals of the ultrasonic generator to be irregular, and a processor configured to control the signal detection sensor and analyze the component of the object based on the signal of light detected by the detector.

Methods and apparatus for enhanced visualization of anomalies in a structure. The method comprises: acquiring pulse-echo laser ultrasonic wave propagation imaging video data at a multiplicity of points in a scan area on a surface of a structure; post-processing the pulse-echo laser ultrasonic wave propagation imaging video data using multiple-time window amplitude mapping to create a multiple-time window amplitude map; and displaying the multiple-time window amplitude map on a graphical user interface.

A method for testing a structure using laser ultrasound includes steps of: (1) directing positioning light on a surface of the structure; (2) determining a spatial location and a spatial orientation of the surface from an evaluation of the positioning light reflected back from the surface; (3) directing pump light onto the surface to generate ultrasonic waves in the structure; (4) selectively locating a probe-light focal point of probe light on the surface, based on the spatial location determined for the surface; (5) selectively angularly orienting the probe light normal to the surface, based on the spatial orientation determined for the surface; and (6) directing the probe light onto the surface to detect a response to the ultrasonic waves.

Provided is an apparatus configured to analyze a component of an object, the apparatus including a signal detection sensor including a light source configured to emit light to the object, a detector configured to detect a signal of light scattered or reflected from the object, an ultrasonic generator configured to transmit an ultrasonic wave toward the object at irregular ultrasonic transmission time intervals to modulate a frequency of the light emitted to the object, and a controller configured to control the ultrasonic transmission time intervals of the ultrasonic generator to be irregular, and a processor configured to control the signal detection sensor and analyze the component of the object based on the signal of light detected by the detector.

A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample, comprising one or more laser sources configured to generate a plurality of excitation beams configured to generate pressure signals in the sample at an excitation location, and a plurality of interrogation beams incident on the sample at the excitation location, a portion of the plurality of interrogation beams returning from the sample that is indicative of the generated pressure signals, an optical system configured to focus the plurality of excitation beams at a first focal point and the plurality of interrogation beams at a second focal point, the first and second focal points being below the surface of the sample, and a plurality of detectors each configured to detect a returning portion of at least one of the plurality of interrogation beams.

In a method of inspecting a structure, a first ultrasonic signal generated from a target structure by a first laser beam is received. The first ultrasonic signal is generated by providing the first laser beam generated from a first excitation unit to the target structure. A second ultrasonic signal generated from the target structure by a second laser beam different from the first laser beam is received. The second ultrasonic signal is generated by providing the second laser beam generated from a second excitation unit to the target structure. A third ultrasonic signal generated from the target structure by the first and second laser beams is received. The third ultrasonic signal is generated by simultaneously providing the first and second laser beams to the target structure. It is determined whether the target structure is damaged based on first, second and third ultrasonic frequency spectra that are obtained by converting the first, second and third ultrasonic signals, respectively.

Disclosed by the present disclosure is a photoacoustic dual-mode imaging probe, which comprises an optical fiber, a transducer and a housing; the optical fiber and the transducer are at least partially housed at the interior of the housing, and a light outlet of the optical fiber and a front end of the transducer are both located at an head end of the photoacoustic dual-mode imaging probe; the optical fiber is used to emit laser pulses; and the transducer is used to transmit and receive ultrasound signals. The photoacoustic dual-mode imaging probe uses the housing to wrap the optical fiber and the transducer inside the housing, such that the three become a whole, thereby being easy to clean and disinfect, being convenient to hold, having strong human-computer interaction performance, and eliminating the use of a coupling pad.