Method for measuring thickness of coatings includes illuminating an automobile sample comprising a substrate and at least one coating with light waves of varying wavelengths from a light source. It further includes receiving the light waves reflected by a top surface and a bottom surface of the coating on the sample at the light collector. It also includes diffracting the light waves into a plurality of component wavelengths with a grating, detecting light intensities of the plurality of component wavelengths at a detector array, generating a combined reflected interference pattern spectral curve using the detected light intensities for each of the received light waves for each of the plurality of component wavelengths, and calculating a thickness of the at least one coating from a frequency of the combined reflected interference pattern spectral curve of the component wavelengths.

A method for measuring a thickness of a coating includes illuminating a substrate of an appliance with light waves of varying wavelengths from a light source. The method further includes receiving the light waves reflected by a top surface and a bottom surface of the coating at a light collector. The method may further include diffracting the light waves into a plurality of component wavelengths with a grating, and detecting light intensities of the plurality of component wavelengths at a detector array. The method may further include calculating a thickness of the coating from the detected light intensities.

An optical filter may include a first reflector and a second reflector. The first reflector may include a plurality of first gratings having a first sub-wavelength dimension and being arranged to recur at a first interval in a first direction. The second reflector may be spaced apart from the first reflector and include a plurality of second gratings having a second sub-wavelength dimension and arranged to recur at a second interval in a direction parallel to the first direction. The first reflector and the second reflector may include different materials or different geometric structures from each other. Accordingly, it is easy to adjust the transmission wavelength characteristics of the optical filter.

A method for measuring the thickness of coatings on a substrate of an aerospace component comprises illuminating a sample comprising the substrate of the aerospace component and a coating with light waves of varying wavelengths from a light source, receiving the light waves reflected by the sample at a light collector, diffracting the light waves into a plurality of component wavelengths with a grating, detecting the light intensities of the plurality of component wavelengths at a detector array, generating a reflectance spectral curve using the detected light intensities for each of the plurality of component wavelengths, calculating the thickness of the coating from the reflectance spectral curves of the component wavelengths.

A spectrometer and a spectral detection and analysis method implemented by the spectrometer. The spectrometer includes an optical device and a detection device. The optical device includes at least one light filter, each of which including at least two light filtering units, so that the optical device can emit at least two kinds of monochromatic light. The detection device includes at least one detector, each of which comprising at least two detection units facing at least two light filtering units in the corresponding light filter in a one-to-one relationship. The monochromatic light emitted from the light filtering unit is emitted along the direction perpendicular to the direction of the light emitting surface.

Spectral analysis system for capturing a spectrum including an inlet opening, a dispersive optical element and reflecting imaging optics having at least one optical functional element defining an optical path from the inlet opening across the dispersive optical element onto an outlet opening and/or detector area of the spectral analysis system and a carrier member defining a flat optical path volume with at least one lateral opening. The dispersive optical element is configured, e.g. in a stationary manner. At least one of the inlet opening, the outlet opening and/or detector area, the at least one optical functional element and the dispersive optical element are integrated in at least one member. The at least one member is mounted on the carrier member at the at least one lateral opening, such that the optical path largely runs transversely to a thickness direction of the optical path volume.

A stray light reducing apparatus includes a light source and an entrance slit positioned to pass through light from the light source. A first monochromator mirror is positioned to reflect light passed through the entrance slit. A diffractive surface is positioned to receive and diffract light reflected by the first monochromator mirror. A second monochromator mirror is positioned to reflect light diffracted by the diffractive surface. An exit slit is positioned to pass through light reflected by the second monochromator mirror. A cuvette is positioned to pass through light passed through the exit slit. A long-pass interference filter is positioned to receive light from the light source, reflect light that has a wavelength below a selected value, and pass through light having a wavelength above the selected value. A first sample detector is positioned to receive light reflected by the long-pass interference filter.

A detection device includes a light emitting element, an accommodation frame, a light detector, and a movable light splitter. The light emitting element provides an excitation beam. The accommodation frame accommodates an object under test, and a portion of the excitation beam whose dominant light emitting wavelength falls within a first waveband range forms a fluorescent beam after passing through the object under test. The light detector receives a portion of the fluorescent beam whose dominant light emitting wavelength falls within a second waveband range. The movable light splitter forms a plurality of sub-beams from an incident beam. The sub-beams have respectively different dominant light emitting wavelengths and exits at different emitting angles. The incident beam is at least one of the excitation beam and the fluorescent beam.

A method for measuring a thickness of a coating includes illuminating a substrate of an appliance with light waves of varying wavelengths from a light source. The method further includes receiving the light waves reflected by a top surface and a bottom surface of the coating at a light collector. The method may further include diffracting the light waves into a plurality of component wavelengths with a grating, and detecting light intensities of the plurality of component wavelengths at a detector array. The method may further include calculating a thickness of the coating from the detected light intensities.

A photovoltaic module comprises at least one photovoltaic cell and one concentration optic device, to be illuminated by a light flux emitting at at least one illumination wavelength belonging to a band of wavelengths defined by a minimum wavelength and a maximum wavelength, the band of wavelengths being that of the solar radiation of the order of [380 nm-1600 nm]. The concentration optic device is a monolithic component and comprises at least one diffractive structure comprising subwavelength patterns, defined in a structured material; the patterns having at least one dimension less than or equal to the average illumination wavelength divided by the refractive index of the structured material; the patterns being separated from one another by subwavelength distances, defined between centres of adjacent patterns; the concentration optic device ensuring at least one focusing function and one diffraction function. A solar panel comprising the photovoltaic module is also provided.