A device that is configured to detect spectrally resolved emission from a material is disclosed. The device includes an optical cavity comprising a pair of substrates separated by a distance defined to restrict a photonic density of states (DOS) of the material to be detected, a detector oriented with respect to the optical cavity to receive emission from the optical cavity and a controller configured to control the distance. The pair of substrates includes facing reflective surfaces.

Various embodiments disclosed herein describe a divided-aperture infrared spectral imaging (DAISI) system that is adapted to acquire multiple IR images of a scene with a single-shot (also referred to as a snapshot). The plurality of acquired images having different wavelength compositions that are obtained generally simultaneously. The system includes at least two optical channels that are spatially and spectrally different from one another. Each of the at least two optical channels are configured to transfer IR radiation incident on the optical system towards an optical FPA unit comprising at least two detector arrays disposed in the focal plane of two corresponding focusing lenses. The system further comprises at least one temperature reference source or surface that is used to dynamically calibrate the two detector arrays and compensate for a temperature difference between the two detector arrays.

Systems, cameras, and software for performing optical gas imaging using thermal imaging. Processors are programmed with instructions for a method of detecting gas that includes creating a filtered background image, a filtered foreground image, and optical gas image data, and generating a display image. The filtered background image and filtered foreground images may be created by combining infrared image data from a plurality of images captured by an infrared camera module using filtering processes. The optical gas image data may be created by comparing the filtered background image and the filtered foreground image. An image may be generated that includes the optical gas image data for presentation on a display.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.

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.

A method and a system for classifying at least one individual gas compound from a plurality of leaked gases in a specified field of view are provided herein. The method may include the following steps: generating, by a cryogenically cooled detector and using a first of at least n filters, multiple spectral band images of the specified view in spectral bands coinciding with said leaking gases spectral bands in which said leaking gases emit and absorb electromagnetic radiation; calculating from the images, the relative absorption response of said gases in each of said filters, respectively; calculating a set of predetermined coefficients; normalizing said relative absorption responses to the sum of relative responses of said filters; and calculating the weighted average molecular mass of said gas compound of said leaking gases.

Provided is a simulation spectrum apparatus including: a background image acquisition unit that acquires a background image of a target region and an infrared signal corresponding to each pixel of the background image; a spectrum acquisition unit that acquires a background radiation intensity spectrum from the infrared signal acquired for the each pixel; a simulation spectrum generation unit that generates a model of a linear combination of a radiation intensity spectrum of a contamination cloud and a background radiation intensity spectrum on the basis of a difference in radiation intensity; a controller that generates a simulation spectrum of the contamination cloud by applying the information on the at least one toxic substance and the atmosphere transmittance to the model of the linear combination; and an imaging unit that generates a spectrum image, combines the generated spectrum image and the background image, and thus generates a simulation contamination cloud image.

A method and a system for classifying at least one individual gas compound from a plurality of leaked gases in a specified field of view are provided herein. The method may include the following steps: generating, by a cryogenically cooled detector and using a first of at least n filters, multiple spectral band images of the specified view in spectral bands coinciding with said leaking gases spectral bands in which said leaking gases emit and absorb electromagnetic radiation; calculating from the images, the relative absorption response of said gases in each of said filters, respectively; calculating a set of predetermined coefficients; normalizing said relative absorption responses to the sum of relative responses of said filters; and calculating the weighted average molecular mass of said gas compound of said leaking gases.

Various embodiments disclosed herein describe a divided-aperture infrared spectral imaging (DAISI) system that is adapted to acquire multiple IR images of a scene with a single-shot (also referred to as a snapshot). The plurality of acquired images having different wavelength compositions that are obtained generally simultaneously. The system includes at least two optical channels that are spatially and spectrally different from one another. Each of the at least two optical channels are configured to transfer IR radiation incident on the optical system towards an optical FPA unit comprising at least two detector arrays disposed in the focal plane of two corresponding focusing lenses. The system further comprises at least one temperature reference source or surface that is used to dynamically calibrate the two detector arrays and compensate for a temperature difference between the two detector arrays.

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.