A measurement method includes: (a) measuring an emission intensity for each wavelength of light detected from a plasma generated in a plasma processing apparatus at each different exposure time by a light receiving element; (b) specifying, with respect to each of a plurality of different individual wavelength ranges that constitutes a predetermined wavelength range, a distribution of the emission intensity in the individual wavelength range measured at an exposure time at which an emission intensity of a predetermined wavelength included in the individual wavelength range becomes an emission intensity within a predetermined range; (c) selecting a distribution of the emission intensity in the individual wavelength range from the distribution of the emission intensity specified in (b); and (d) outputting the distribution of the emission intensity selected for each individual wavelength range.

Provided is a spectral sensor array, including: a planar waveguide on a substrate; a chirped input coupling grating, wherein the chirped input coupling grating comprises a transverse chirp to provide a spectrally selective coupling of incident light into the planar waveguide; an output coupling grating; and an array of photodetectors arranged to receive the light coupled out of the waveguide.

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.

Hyperspectal imagers including reflective and transmissive metasurfaces are disclosed. The described metasurfaces are used collectively to disperse and focus light of different wavelengths and incident angles on a focal plane. The disclosed devices are compact and light, and can be used in systems and applications requiring stringent form factors.

A time-resolved hyper-spectral imaging system for imaging a sample, includes a radiation source suitable for illuminating the sample repeatably, a first optical system configured to form an image I of the sample on a spatial light modulator forming a transmission or reflection mask P, a processor connected to the spatial light modulator and configured to make the transmission or reflection mask P vary for each repetition of the illumination, a second optical system suitable for focusing the radiation transmitted or reflected by the spatial light modulator so as to form, in its image focal plane, a partial image S=P.Math.I; the imaging system being wherein it comprises: a dispersive device comprising a slit placed in the image focal plane of the second optical system, the dispersive device being suitable for spatially splitting the various wavelengths of the radiation transmitted or reflected by the spatial light modulator; a streak camera arranged so as to be illuminated by the radiation issuing from the dispersive device and configured to acquire a plurality of time-resolved partial images of the sample, the images being associated with respective and different transmission or reflection masks P, the streak camera being connected to the processor and the processor also being configured to combine the partial images of the sample so as to construct a 4D image cube I.sub.tot forming an image resolved in time and in wavelength of the sample; and corresponding time-resolved hyper-spectral imaging method for imaging a sample.

Spectrometer systems are provided including a detector array; an imaging lens assembly coupled to the detector array, the imaging lens assembly including a first element of positive optical power followed by a second element of negative optical power and a positive optical power element split into two opposing identical singlets; a dispersive element coupled to the imaging lens assembly; and a fixed focus collimator assembly coupled to the dispersive element. Related imaging lens assemblies and collimator assemblies are also provided.

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 includes a transparent substrate including a first surface and a second surface that face each other and are substantially parallel to each other; a slit provided on the first surface and through which light is incident onto the transparent substrate; a spectrum optical system including metasurface including a plurality of nanostructures that are two-dimensionally arranged and satisfy a sub-wavelength scattering condition, wherein the metasurface includes a focusing metasurface which includes first nanostructures of the plurality of nanostructures, and is configured to reflect, disperse, and focus the light incident thereon through the slit, at different angles based on respective wavelengths; and a sensor configured to receive the light from the focusing metasurface. When L is a total length of an optical path from the slit to the sensor and D is a thickness of the transparent substrate, L and D satisfy the following inequality: L/D>3.

A system for performing advanced spectrometry using a camera of a personal electronic device. Light from a sample is captured via a light dispersion device that diffracts the light in accordance with the wavelength of that light. A sample spectrum image is captured using a camera of a personal electronic device. Spectral data is extracted from the sample spectrum image and the spectral data is wavelength calibrated by mapping each pixel position in the sample spectrum image to a wavelength. Features are extracted from the wavelength calibrated spectral data and used by classification module, trained on a dataset of features extracted from spectral data of known samples, to classify the sample. In some embodiments, a calibration spectrum image captured from a calibration light source having a known spectrum (e.g., in the same image frame using a bifurcated fiber optic cable) is used to wavelength calibrate the spectral data.

An electronic device such as a portable electronic device may include a single-shot alignment-free spectrometer with no moving parts. The spectrometer may include a diffractive member, such as a grating, an aperture, and an image sensor that generates data in response to incident light. The diffractive member may diffract the incident light based on its wavelength and angle of incidence, and the aperture may further encode the light. The data generated by the image sensor may be used by control circuitry in combination with correlations between spectrometer measurements and known light profiles to determine the wavelength and angle of incidence of the light. These correlations may be determined using a deep neural network. Control circuitry may adjust one or more settings of the electronic device based on the wavelength and angle of incidence, or may use the wavelength and angle of incidence to determine information regarding an external object.