A method of analyzing a material (12) comprising at least one analyte, said method comprising a material status analyzing procedure (76), in which a present status of the material is analyzed, wherein based on a result of said material status analyzing procedure (76), at least one of a selection of analyte-characteristic-wavelengths used during an analyte measurement procedure (78), an absolute time or a relative time proportion of use of analyte-characteristic-wavelengths during said analyte measurement procedure (78), an individual excitation radiation intensity, or a relative weight given to the wavelengths in the analysis, a selection of analyte-characteristic-wavelengths to be used simultaneously during said analyte measurement procedure (78), and a selection of one or more main frequencies of the modulation of said excitation radiation (18) intensity to be used during said analyte measurement procedure (78) is determined.

The invention comprises an applied force-optic analyzer used to determine a sample constituent concentration, a physical measure of the sample, and/or a state of the sample. The analyzer comprises: an electro-mechanical transducer affixed to skin of a subject; a controller, the controller providing a voltage waveform to the electro-mechanical transducer driving displacement of the skin and inducing a pressure wave into the skin; and a spectrometer interfaced to a sample site of the skin, the spectrometer comprising a set of sources and a set of detectors, where the controller is configured to collect signal from the set of detectors as a function of timing of the voltage waveform and apply a calibration model to the signal to determine the analyte concentration.

A method refocuses on an optical assembly target surface, using at least one beam originating from a short-pulse optical source, having at least one optical system for focusing the beam on the surface. Refocusing occurs after learning reference conditions for which the assembly is considered as focused. A focusing signal is detected representing a time overlap of the pulses between a beam reflected and a reference beam not reflected by the surface and comes from the source, one of the beams delayed by a delay line, the beam optical path on which the delay line is placed is varied, on the basis of the reference conditions, to cause the focusing signal to reach or go beyond a predetermined threshold. The focus is adjusted on the basis of variation knowledge in the path between the reference conditions and the conditions for which the focusing signal reaches or goes beyond the threshold.

A method of analyzing a material (12) comprising at least one analyte, wherein analyte-wavelength-specific measurements are interspersed with reference measurements (80), and wherein response signals obtained for the reference measurements (80) are used for one or more of calibrating an excitation radiation source (26) for generating said excitation radiation, calibrating said detection device, recognizing a variation in the measurement conditions by comparing results of individual reference measurements (80), adapting the analyte measurement procedure (78) with respect to one or more of the entire duration thereof, the absolute or relative duration of analyte-wavelength-specific measurements for a given analyte-characteristic-wavelength, or terminating and/or restarting the analyte measurement procedure, and adapting the analysis carried out in the analyzing step.

The present disclosure discloses a measurement method and an optical device for measuring an in-plane thermal conductivity of a sub-millimeter-scale sample. The optical device includes a first continuous-wave laser connected to a signal source; a second continuous-wave laser for outputting a detection laser, wherein a half-wave plate, a polarized beam splitter, a quarter-wave plate, a dichroic mirror, an objective lens, reflectors, a balanced photodetector, and a lock-in amplifier are sequentially arranged along an optical path of the detection laser, wherein the dichroic mirror is configured to allow transmission of the detection laser and reflection of the heating laser; the polarized beam splitter reflects part of the detection laser to the balanced photodetector and the detection laser reflected from the sample is reflected to the balanced photodetector, the balanced photodetector converts a laser signal into an electrical signal; the lock-in amplifier extracts an amplitude and a phase of the electrical signal.

Photoacoustic detecting device (1), intended to be applied, via a contact face (3), against a medium to be analysed, the device comprising: a hollow cavity (20) comprising a first aperture (22) produced in the contact face, the cavity being bounded by a containment shell (21) that extends around the first aperture; a pulsed or amplitude-modulated light source (10) configured to emit, in an emission spectral band (Δλ), an incident light wave (11) through the cavity (20) to the first aperture; an acoustic transducer (28) linked to the cavity and configured to detect a photoacoustic wave (12) extending through the cavity. The photoacoustic detecting device is optimized to increase the amplitude of the photoacoustic wave detected by the acoustic transducer.

A photo-thermal speckle spectroscopy device having an infrared laser, a visible laser, a foam, and a camera. The infrared and visible lasers are focused on the foam, which causes the visible laser to scatter. A camera records the speckle pattern, which shifts when the IR laser is turned on. The related method of photo-thermal speckle spectroscopy is also disclosed.

The present invention provides a gas measuring method based on photothermal effect in hollow-core optical fiber comprising: filling a target gas into the core of a hollow-core optical fiber; coupling a probe light and a periodically modulated pump light into the hollow-core optical fiber; absorbing the pump light by the target gas resulting in the periodic modulation of the phase of the probe light; demodulating the phase modulation information of the probe light to obtain the concentration of the target gas, wherein the pump laser is wavelength and/or amplitude modulated. In the present invention, two lasers including a pump laser and a probe laser are used for the measurement, this approach is simple and practical. Also, the use of the hollow-core optical fiber with extremely-small core area greatly increases the optical power density, thus enhances the strength of the detected photothermal signal; this method allows ppb level gas measurement with high selectivity, and is universally suitable for the detection of gases with absorption in near-infrared.

Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample.

Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample. The setup may be implemented in a disc and optical pick-up head configuration.