A spectroscopic module includes a plurality of beam splitters that are arranged along an X direction; a plurality of bandpass filters disposed on one side in a Z direction with respect to the plurality of beam splitters facing the plurality of beam splitters, respectively; a light detector disposed on the one side in the Z direction with respect to the plurality of bandpass filters and including a plurality of light receiving regions facing the plurality of bandpass filters, respectively; a first support body supporting the plurality of beam splitters; and a second support body supporting the plurality of bandpass filters. The second support body includes a support portion in which a support surface is formed so as to be open to the one side in the Z direction. The plurality of bandpass filters are disposed on the support surface.

Techniques for optical detection of target chemicals on/in samples are disclosed. Light of at least two different wavelengths, or different bands of wavelengths, interacts with a target chemical, and at least some of the light that has interacted with the target chemical is incident on at least two photodetectors. Each of the photodetectors is configured to detect light of a different wavelength, or a different band of wavelengths, that has interacted with the target chemical. A processing logic is configured to compute a ratio between a parameter indicative of the intensity of light detected by one photodetector and a parameter indicative of the intensity of light detected by the other photodetector, and to determine the presence and/or the amount of the target chemical based on the computed ratio. In this manner, a simple, compact, and non-contact optical measurement assembly for assessing chemical content using differential spectral measurements may be provided.

Apparatus and methods for acquiring a Raman spectral map of a sample including a material species. The apparatus includes: a pulsed illumination source providing pulsed illumination radiation for exciting the sample and producing scattered radiation; a microscope objective focusing the pulsed illumination radiation onto a region of the sample corresponding to a data point of the map, and collecting emitted radiation from the region; a translation stage translating the sample relative to the microscope objective in at least two directions; a spectral filter spectrally filtering the emitted radiation collected by the objective to obtain a filtered portion of radiation corresponding to a characteristic Raman spectral feature of the material species; a detector receiving the filtered portion and providing output electrical pulses indicative thereof; and readout electronics applying a time gate to the output electrical pulses to distinguish detection events corresponding to the Raman scattered radiation from events associated with photoluminescence.

A gas analysis system with an FTIR spectrometer preferably utilizes a long path gas cell, a narrow band detector, and an optical filter that narrows the detection region. The interferograms are further prevent baseline drift and analyze the resultant spectra.

A filter array according to one aspect of the present disclosure is provided with filters arranged two-dimensionally. The filters include multiple types of first filters having mutually different transmission spectra, of which each transmission spectrum includes first peaks, and multiple types of second filters having mutually different transmission spectra, of which each transmission spectrum includes one or more second peaks. The number of the first peaks in the transmission spectrum of each of the multiple types of first filters is greater than the number of the one or more second peaks in the transmission spectrum of each of the multiple types of second filters, and the multiple types of first filters and the multiple types of second filters are disposed in a mixed arrangement.

A system, apparatus and method of improved measurement of the SPF factor of sunscreen compositions. In one embodiment, a method of measuring the protection of a sunscreen composition includes exposing skin to a known intensity of light, measuring the amount of remitted light from the skin, applying sunscreen to the skin, exposing the skin to which the sunscreen has been applied the known intensity of emitted light of the spectrum of light from which the sunscreen is intended to protect the skin, measuring the amount of light remitted from the skin, and calculating a UltraViolet-A Protection Factor (UVA-PF) of the sunscreen by comparing the amount of light remitted from the skin with the sunscreen to the amount of light remitted from the skin without the sunscreen.

Devices and methods to perform Raman spectroscopy with a structured excitation profile to obtain a Raman excitation map. A device includes a broadband light source to emit a broadband light beam and excitation optics to disperse the broadband light beam to strike a sample as incident light according to a structured excitation profile. The device further includes analysis optics to collect scattered light scattered by the incident light striking the sample, block Rayleigh scatter from the collected scattered light in a manner complementary to the structured excitation profile, and direct Raman scatter from the collected scattered light to a sensor to generate a signal to form a Raman excitation map.

A method for enhancement of spontaneous Raman scattering (SRS) from gases comprising a multimode blue laser diode which receives feedback from a near concentric bidirectional multipass cavity in such a way as to generate a circulating power of order 100 W for a sample volume of 10 mm.sup.3. The feedback, provided via a volume Bragg grating, reduces the laser bandwidth to 4 cm.sup.−1. Spectra of spontaneous Raman scattering from ambient atmospheric air, detected collinearly with the pump, were recorded with a limit of detection below 1 part-per-million.

A spectrally-shaped source includes a source that generates a round beam. An optical element transforms the round beam to a rectangular beam. An image forming dispersive device angularly disperses wavelengths and images the rectangular beam at a modulation plane. A pixelated SLM is illuminated by the dispersed wavelengths of the rectangular beam such that each column of illuminated pixels is illuminated by a different wavelength. Toroidal optics projects light directed from the SLM to an output plane and focuses the angularly dispersed wavelengths of the beam so that a selected portion of the optical beam is reflected toward the toroidal optic by the SLM. A controller instructs the pixelated SLM to selectively reflect the portion of the optical beam toward the toroidal optic and to selectively reflect another portion of the beam away from the toroidal optic so as to provide a desired spectral shape.

The measurement of solar irradiance measurement have important applications, including solar resource assessment, solar power plants, photovoltaic system monitoring, heating and cooling loads of buildings, climate modeling and weather forecasting. An option to establish this is to solely measure the global horizontal irradiance and employ an irradiance decomposition algorithm to derive direct normal irradiance and diffuse horizontal irradiance. However, these models vary in complexity and generally have a relatively high uncertainty particularly between latitudes +60° N and −45° S these errors which includes large portions of North America, Europe, Russia, and Asia where the applications are centered. The inventors have established an improved methodology based upon an improved decomposition algorithm yielding improved accuracy in derived solar irradiance measurements in conjunction with a low cost non-moving part spectral pyranometer supporting spectral global irradiance measurements and spectral clearness indices.