There are disclosed methods and apparatus for measuring water content in tissue in-vivo, for example in sub-surface or sub-cutaneous tissue of a human or animal subject. The measurement may be made through diffusely scattering overlying tissue such as skin tissue, by: directing probe light to an entry region on a surface of the overlying tissue; collecting said probe light from a collection region on the surface of the overlying tissue, the collection region being spatially offset from the entry region, the collected probe light comprising probe light inelastically scattered into the Raman OH stretching bands by water present in the sub-surface tissue; detecting, in the collected probe light, one or more first spectral features of the probe light inelastically scattered into the Raman OH stretching bands; and measuring water content in the sub-surface tissue using the one or more first spectral features.

Aspects of embodiments pertain to a sensing systems configured to receive scene electromagnetic (EM) radiation comprising a first wavelength (WL1) range and a second wavelength (WL2) range. The sensing system comprises at least one spectral filter configured to filter the received scene EM radiation to obtain EM radiation in the WL1 range and the WL2 ranges; and a self-adaptive electromagnetic (EM) energy attenuating structure. The self-adaptive EM energy attenuating structure may comprise material that includes nanosized particles which are configured such that high intensity EM radiation at the WL1 range incident onto a portion of the self-adaptive EM energy attenuating structure causes interband excitation of one or more electron-hole pairs, thereby enabling intraband transition in the portion of the self-adaptive EM energy attenuating structure by EM radiation in the WL2 range.

Provided are an optical spectrum analyzer and a pulse-modulated light measurement method capable of measuring pulse-modulated light even when a pulse-on time and a pulse period of the pulse-modulated light are unknown. Pulse-modulated light (DUT) is incident on a diffraction grating 3. A first light receiving unit 8 receives the 0th-order light of diffracted light diffracted by the diffraction grating 3. A second light receiving unit 7 receives diffracted light of an order other than the 0th-order light. A measurement timing signal generation unit 9 generates a sampling signal based on the 0th-order light received by the first light receiving unit. The spectrum of the diffracted light received by the second light receiving unit is measured based on the sampling signal generated by the measurement timing signal generation unit.

Methods and systems for automatically adjusting a sample position in a spectrometer, such as a Fourier-transform infrared (FTIR) spectrometer, are described. The sample may be automatically positioned using an auto-focusing procedure. For example, images including an aperture marker are acquired by directing light towards the sample via an aperture. The sample position may be adjusted based on features extracted from the aperture marker images.

In a Raman microscope, a depth measurement processor performs depth measurement by changing a focal position of laser light along a depth direction of a sample which is an irradiation direction of the laser light with respect to the sample, and meanwhile, acquiring a Raman spectrum of the sample at a plurality of points in the depth direction. The display processor causes Raman spectra obtained at the plurality of points by the depth measurement to be displayed. The display processor can display a surface image of the sample on the stage and a depth image representing a plurality of points in the depth direction and causes, in a case where at least one point of the plurality of points in the depth image is selected, the Raman spectrum corresponding to the at least one point to be displayed.

In a Raman microscope, a depth measurement processor performs depth measurement by changing a focal position of laser light along a depth direction of a sample which is an irradiation direction of the laser light with respect to the sample, and meanwhile, acquiring a Raman spectrum of the sample at a plurality of points in the depth direction. A display processor displays an input screen used to input a parameter at a time of performing the depth measurement on the sample in association with a surface image of the sample on a stage. The parameter includes a range in which the focal position of the laser light is changed along the depth direction and an interval between the plurality of points within the range.

System for performing chemical spectroscopy on samples from the scale of nanometers to millimeters or more with a multifunctional platform combining analytical and imaging techniques including dual beam photo-thermal spectroscopy with confocal microscopy, Raman spectroscopy, fluorescence detection, various vacuum analytical techniques and/or mass spectrometry. In embodiments described herein, the light beams of a dual-beam system are used for heating and sensing.

A tunable spectral filter includes a first tunable dispersive element, a first optical element, a spatial filtering element located at the focal plane, a second optical element, and a second dispersive element. The first tunable dispersive element introduces spectral dispersion to an illumination beam with an adjustable dispersion. The first optical element focuses the illumination beam at a focal plane in which a distribution of a spectrum of the spectrally-dispersed illumination beam at the focal plane is controllable by adjusting the dispersion of the first tunable dispersive element. The spatial filtering element filters the spectrum of the illumination beam based on the distribution of the spectrum of the illumination beam at the focal plane. The second optical element collects the spectrally-dispersed illumination beam transmitted from the spatial filtering element. The second tunable dispersive element removes the dispersion introduced by the first tunable dispersive element from the illumination beam.

An apparatus configured to detect a substance, and method of operating and forming the same. In one embodiment, the apparatus includes a tunable resonator including an upper Bragg reflector and a lower Bragg reflector separated by a porous matrix. The tunable resonator is configured to be illuminated by a light source and produce a first spectral optical response from a substance absorbed within the porous matrix. The apparatus also includes a detector positioned proximate the tunable resonator configured to provide a first absorption signal representing the first spectral optical response.

According to an example embodiment, a detector assembly for use in analysis of elemental composition of a sample by using optical emission spectroscopy is provided, the detector assembly including a rotatable element that is rotatable about an axis and that has attached thereto a laser source for generating laser pulses for invoking optical emission on a surface of the sample, the laser source arranged to generate laser pulses focused at a predefined distance from said axis at a predefined distance from a front end of the detector assembly, and a detector element for capturing optical emission invoked by said laser pulses.