A coherence gated photoacoustic remote sensing system for imaging a subsurface structure in a sample with optical resolution may include an excitation beam source configured to generate an excitation beam that induces ultrasonic signals in the sample at an excitation location; an interrogation team source configured to generate an interrogation team incident on the sample at an interrogation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals, the interrogation beam being a low-coherent beam; an optical system that focuses the excitation beam onto the sample at an excitation location, and focuses the interrogation beam onto the sample at an interrogation location, at least the interrogation location being below the surface of and within the sample; and a low coherence interferometer that isolates a returning portion of the interrogation beam that corresponds to an interrogation event of the sample.

The invention relates to a device (1) and a corresponding method for mid-infrared microscopy and/or analysis, the device (1) comprising at least one radiation unit (10) configured to generate radiation (11) of time-varying intensity, the radiation (11) comprising one or more wavelengths in the mid-infrared spectral range, at least one refractive and/or reflective optical unit (12) which is configured to focus and/or direct the radiation (11) to at least one region or point of interest (20) located on and/or within an object (2), at least one detection unit (18) configured to detect ultrasound waves (17) emitted by the object (2) at the at least one region or point of interest (20) in response to an interaction of the radiation (11) with the object (2) and to generate according detection signals, and an evaluation unit (25) configured to derive information regarding at least one property of the object (2) from the detection signals and/or to generate a spatial and/or spatio-temporal distribution of the detection signals or of information derived from the detection signals obtained for the at least one region or point of interest (20) located on and/or within the object (2).

Technologies are generally described for normalized standard deviation transition based dosimetry monitoring for laser treatment. In some examples, a response signal may be generated based on a physical response to a laser pulse detected through acoustic or optical means. Each response signal may be a time series of data with a number of points. Standard deviation may be determined for each response signal and normalized using a mean or comparable normalization factor. Thus, a robust distribution may be computed from the response to each laser pulse. A change in the normalized standard deviation from each single pulse's time domain response data may be used to determine how many laser pulses remain before completion of the treatment (similar to event onset response). Thus, laser treatment may be continued based on an estimation of remaining pulses for completion or ceased if completion is reached.

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.

The invention relates to a photoacoustic method comprising a measurement light having a predefined wavelength range for determining properties of an inhomogeneous sample, the sample having a mean absorption length from the range of 1 to 100 micrometers for the predefined wavelength range, the method comprising the following steps: a) radiating at least one measurement light pulse having a predefined pulse duration and a predefined intensity onto a measurement area of the area F with F>> in the surface of the inhomogeneous sample; b) detecting at least one pressure transient at the measurement area, the pressure transient resulting from the absorption of the at least one measurement light pulse in the inhomogeneous sample with production of a pressure wave propagating to the measurement area; c) calculating a value for the energy density absorbed by the sample during the pulse duration from the curve of the at least one pressure transient at the start and at the end of the at least one measurement light pulse; characterized by d) repetition of steps a) to c) for different angles of incidence of the measurement light with respect to the normal of the measurement area, the energy density values determined in c) each being indicated with the angle of incidence; e) modeling 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; f) performing a fitting procedure for the fitting parameters of the stack of layers, the division of the energy density values indicated with the angle of incidence into contributions of the individual layers being varied by variation of the fitting parameters until a predefined consistency criterion is met; g) reading out the fitted fitting parameters as values at least for the depth-resolved absorption coefficient of the inhomogeneous sample.

Methods and apparatuses for manufacturing are disclosed, including (a) providing an apparatus having: a laser; a scanner; a powder injection system; a powder spreading system; a dichroic filter; an imager-and-processor; and a computer; (b) programming the computer with structural and material specifications of a sample; (c) using the computer to set initial parameters based on the structural and material specifications of the sample; (d) adjusting a stage to position the sample; (e) focusing and scanning electromagnetic radiation onto the sample while powder is concurrently injected onto the sample in order to deposit a layer; (f) capturing two-dimensional images of the sample and probing the sample to determine whether the deposited layer was manufactured per the structural and material specifications; (g) use the computer to adjust the three-dimensional manufacturing parameters based on the determination made in step (f) prior to additively manufacturing a subsequent layer or making repairs; and (h) repeating steps (d), (e), (f), and (g) until the manufacture is complete. Other embodiments are described and claimed.

A method for sourcing plants includes performing nondestructive near-infrared (NIR) scans on selected plants, determining a predicted value of a characteristic for the selected plants based on evaluation of spectral data from the NIR scans against a characteristic model, and utilizing the predicted values for purchasing, processing, and/or financial forecasting. A method of sorting and processing plants includes determining a predicted value of a characteristic in gathered plants and determining a process to recover a primary product and/or a byproduct of the plants based on the predicted value. A method for forecasting includes determining a composite value of a characteristic in plants from a prior time period, correlating source data of plants to be gathered in the later time period with a predicted value of the characteristic in those plants, and determining a predicted composite value of the characteristic in the plants to be gathered in the later time period.

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.

Methods and systems are described for determining layer thickness for layers in a multi-layer sample. Reference transmission spectral data may be determined for a first layer and a second layer. The first layer may comprise a first material associated with a first spectral band and the second layer may comprise a second material associated with a second spectral band. The first spectral band may at least partially overlap the second spectral band. The reference spectral data may be used to determine correction factors. Spectral data may be measured for the multi-layer sample. The correction factors may be used to correct the spectral data by removing the contribution of the second layer from spectral data associated with first layer.

According to one embodiment, an optical test apparatus includes a pump beam generating unit, a probe beam generating unit, and a photodetector. The pump beam generating unit is configured to irradiate a first surface region of a test object with a pump beam having a first wavelength which is transmitted through a first region including the first surface region and a first inner region adjacent to the first surface region and absorbed by an absorber arranged in the first inner region. The probe beam generating unit is configured to irradiate a second surface region outside the first surface region with a probe beam having a second wavelength which is reflected by the second surface region. The photodetector is configured to receive the probe beam reflected by the second surface region.