A method comprises non-destructive contact-free physical characterization of a sample by repeated excitations of the surface of a sample with a sequence of pulses comprising at least one pump pulse by a first “pump” laser followed by a succession of L temporarily offset pulses by a second “probe” laser, and the analysis of the beam emitted by the surface of the sample by an activated photodetector, for the acquisition of signals delivered by the photodetectors during constant time windows.

Photoreflectance (PR) spectroscopy system and method for accumulating separately a “pump on” light beam and a “pump off light beam reflecting off a sample. The system comprises: (a) a probe source for producing a probe beam, the probe beam is used for measuring spectral reflectivity of a sample, (b) a pump source for producing a pump beam, (c) at least one spectrometer, (d) a first modulation device to allow the pump beam to alternatingly modulate the spectral reflectivity of the sample, so that, a light beam reflecting from the sample is alternatingly a “pump on” light beam and a “pump off light beam, (e) a second modulation device in a path of the light beam reflecting off the sample to alternatingly direct the “pump on” light beam and the “pump off light beam to the at least one spectrometer, and (f) a computer.

The invention relates to an apparatus (1; 1a; 1b; 1c) and a method for determining a material property of a test specimen (5; 5a; 5b; 5c) in a test specimen region (6; 6a; 6b; 6c) near the surface, said apparatus comprising at least one electromagnetic radiation source (2; 2a; 2b; 2c) for irradiating at least one surface region (4; 4a; 4b; 4c) of the test specimen, and a detection device (8; 8a; 8b; 8c) for detecting thermal radiation (9; 9a; 9b) emitted by the surface region and/or for detecting radiation (31) reflected from the surface region (4; 4a; 4b; 4c) of the test specimen. An evaluation device (13; 13a; 13b; 13c) for ascertaining the material property to be determined on the basis of the emitted thermal radiation (9: 9a: 9b) and/or the reflected radiation (31) is expediently provided. Advantageously, it is possible for the material property to be determined particularly reliably and nondestructively.

There is provided a method of detecting a change of a state of a liquid comprising the steps of: •providing a liquid detection medium (12) comprising a liquid and having a plurality of anisotropic magnetic particles suspended therein; •applying a modulated magnetic field across at least a portion of the liquid detection medium (12), wherein the magnetic field induces an alignment of the magnetic particles; •introducing electromagnetic radiation (22) into the liquid detection medium (12); •detecting a variable which is modulated by the applied magnetic field, wherein the variable is associated with the interaction of the electromagnetic radiation (22) with the magnetic particles and wherein the change in the state of the liquid causes a variation in the detected variable; and •correlating the variation in the detected variable with the change in the state of the liquid.

Laser light is emitted from a laser into a scattering layer. An ultrasound signal is emitted into a sample. A signal is generated with a light detector in response to a measurement beam of laser light exiting the light scattering layer into the light detector. At least a portion of the measurement beam formed between the laser and the light detector is wavelength-shifted by the ultrasound signal subsequent to the ultrasound signal propagating through the sample.

A terahertz gas spectrometer detection system is provided. The system includes: a terahertz generation module, a gas module, a terahertz detection module and a program-control and acquisition module. terahertz generation module is configured for generating and transmitting terahertz signals with different frequencies; gas module is configured for setting and storing to-be-detected gas, so that terahertz signals with different frequencies pass through the to-be-detected gas; terahertz detection module is configured for detecting amplitude signals of terahertz signals after passing through the to-be-detected gas through field effect transistor detector; program-control and acquisition module is configured for controlling the terahertz generation module to generate and transmit frequency of terahertz signal, and is further configured for acquiring amplitude detection signals of terahertz signals after passing through the to-be-detected gas, and generating spectrogram of to-be-detected gas.

Disclosed herein are thermoreflectance enhancement coatings and methods of making and use thereof.

An optogalvanic effect (OGE) detection system utilizes an intracavity sample cell and a circuit that provides low noise stable excitation and maintenance of a radio frequency (rf) driven gas discharge within the sample cell and a direct current output proportional to the if driving voltage, associated monitoring devices and software. When an optical stimulus interacts with the discharge, any electrical change in the discharge can be simply determined with high precision and accuracy by measuring the impedance of the discharge via a measurement of the direct current output. In a preferred embodiment the rf gas discharge is created with a series resonant oscillator with two push pull sections connected together to generate the high voltage signal. A current source provides a low noise stable current to power the oscillator sections. A band pass amplifier filters the current of the discharge prior to measuring it.

Systems and methods for detecting photothermal effect in a sample are described herein. In these systems and methods, a pump source is configured to generate a pump pulse train, a probe source is configured to generate a probe pulse train and is synchronized with the pump pulse train, and a camera collects the resulting data. The camera is configured to collect a first signal corresponding to a hot frame, wherein the hot frame includes visible probe beam as modified by a pump beam and a second signal corresponding to a cold frame, wherein the cold frame includes visible probe beam that has not been modified by a pump beam. A processor can subtract the second signal from the first signal to detect the photothermal effect.

A system for imaging, including a source of coherent light; a polarization state generator for generating polarized optical photons from the light originating in the source of coherent light; a sample environment; a polarization state analyzer for permitting photons having a desired polarization to interact with a detector; and an imaging unit for generating an image based on the interactions of the photons with the detector. The sample environment includes a plurality of electromagnets, each connected to one or more power supply components; and a controller, connected to the electromagnets and including software for generating and controlling a desired magnetic field created by each of the electromagnets in concert with each other.