A method for true-to-sample measurement by a mobile ingredient analysis system having a housing with a window, an interface for an external reference unit, a display and operating unit, a light source, an optical spectrometer, a camera, an internal reference unit, and an electronic control unit. The method includes: selecting a calibration product suitable for a sample to be examined; performing a plausibility check of the calibration product, an incorrect selection being signaled and an alternative calibration product being selected; outputting measurement conditions comprising the measurement point to be selected and measurement duration for the selected calibration product; capturing measured values of the sample by the spectrometer under the measurement conditions and with simultaneous monitoring of the measurement conditions; processing the captured measured values by means of an electronic control unit, each measured value captured while the measurement conditions were met being declared valid; outputting the measured values deemed valid.

Vegetation change information properly indicating a time series change of a vegetation state can be generated. To this end, a data group including vegetation data of multiple time points respectively associated with ratio information which is a component ratio of ambient light is an object to be processed. This device includes an extraction section that extracts, from the data group, vegetation data for use by using ratio information, and a generation section that generates vegetation change information indicating a time series change of a vegetation state by using the vegetation data extracted by the extraction section. By use of ratio information, vegetation data obtained under similar ambient light conditions can be collected.

A spectroscopy system includes a plurality of light sources, a plurality of detectors, and control circuitry. The control circuitry may be configured to control each light source to output frequency modulated light beams into an object and receive detector-specific data from the detectors. The detector-specific data may be representative of scattered and unabsorbed light resultant from the frequency modulated light beams interacting with the object. The control circuitry may be further configured to determine, for a source-detector link defined by a pairing of a first light source with a first detector, a link phase differential based on received phase information extracted from the detector-specific data for the source-detector link and source phase information of a first frequency modulated light beam from the first light source. Also, the control circuitry may be configured to determine a source-detector link quality metric for the source-detector link based on the link phase differential.

A transmission type color calibration chart includes a transparent substrate and a color bar group formed on the transparent substrate, wherein the color bar group is constituted by color bars of a plurality of colors containing at least a first color and a second color arranged in a pattern in no particular order, coordinate points of the first color are within a region encompassed by the four points (0.351, 0.649), (0.547, 0.453), (0.380, 0.506) and (0.433, 0.464) on an xy chromaticity diagram, coordinate points of the second color are within a region encompassed by the four points (0.125, 0.489), (0.112, 0.229), (0.270, 0.407) and (0.224, 0.242) on an xy chromaticity diagram, and the transmission spectrum of the first color's color bar and the transmission spectrum of the second color's color bar have peak tops that are respectively separated.

Methods and systems are provided for separating polarized UV light. In one example, a method may include passing polarized source light through a group of at least four prisms to collimate and separate a second-harmonic generation (SHG) beam from a pump beam. The separated SHG beam may then be further passed through a spatial filter to reduce spatial distribution.

Described herein is a wavelength reference device comprising a housing defining an internal environment having a known temperature. A broadband optical source is disposed within the housing and configured to emit an optical signal along an optical path. The optical signal has optical power within a wavelength band of interest. An optical etalon is also disposed within the housing and positioned in the optical path to filter the optical signal to define a filtered optical signal that includes one or more reference spectral features having a known wavelength at the known temperature. The device also includes an optical output for outputting the filtered optical signal.

A measurement device characterizes an environment. The measurement device includes a transmitter and a receiver. The transmitter transmits a transmitted light. The transmitter includes an atomically two-dimensional material for emitting the transmitted light. The atomically two-dimensional material is tunable to select a predominate wavelength of the transmitted light within a tunable range of wavelengths. The receiver receives a received light, which is the transmitted light after encountering the environment. The receiver characterizes the environment from a measured change between the received light and the transmitted light.

A method for determining a calibration function includes: calculating a first distance, between a distribution of target spectra and a comparison distribution of spectra; calibrating the distribution of target spectra with a first preliminary calibration function to form a first distribution of calibrated target spectra; calculating a second distance, between the first distribution of calibrated target spectra and the comparison distribution of spectra; determining that the second distance is less than the first distance; and setting the calibration function equal to the first preliminary calibration function.

A method is presented for determining path length fluctuations in an interferometer using a reference laser with an arbitrary frequency with respect to the measured light. The method includes: injecting reference light along signal paths of the interferometer; measuring interference between the reference light at an output of the interferometer; determining an optical phase difference between the reference light in the two signal paths of the interferometer by measuring intensity modulation of the interference between the reference light and subtracting an intended frequency modulation from the measured intensity modulation; accumulating an unwrapped phase difference between the reference light in the two signal paths of the interferometer, where the unwrapped phase difference is defined in relation to a reference; and determining path length fluctuation of light in the interferometer using the unwrapped phase difference.

An infrared (IR) imaging system for determining a concentration of a target species in an object is disclosed. The imaging system can include an optical system including a focal plane array (FPA) unit behind an optical window. The optical system can have components defining at least two optical channels thereof, said at least two optical channels being spatially and spectrally different from one another. Each of the at least two optical channels can be positioned to transfer IR radiation incident on the optical system towards the optical FPA. The system can include a processing unit containing a processor that can be configured to acquire multispectral optical data representing said target species from the IR radiation received at the optical FPA. One or more of the optical channels may be used in detecting objects on or near the optical window, to avoid false detections of said target species.