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. One of the at least two detector arrays comprises a cooled mid-wavelength infra-red FPA. 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 integrated polarization interferometer includes a polarization beam splitter for separating incident complex waves, a first mirror attached to a first surface of the polarization beam splitter, for reflecting a first polarization transmitted through the polarization beam splitter to the polarization beam splitter, and a second mirror attached to a second surface of the polarization beam splitter, for reflecting a second polarization transmitted through the polarization beam splitter to the polarization beam splitter. Accordingly, it is possible to measure dynamic spectroscopic polarization phenomenon with extremely high robustness disturbances due to an external vibration and the like by using the integrated polarization interferometer, thereby improving measurement repeatability and accuracy of measurement.

A spectral imaging system configured to obtain spectral measurements in a plurality of spectral regions is described herein. The spectral imaging system comprises at least one optical detecting unit having a spectral response corresponding to a plurality of absorption peaks of a target chemical species. In an embodiment, the optical detecting unit may comprise an optical detector array, and one or more optical filters configured to selectively pass light in a spectral range, wherein a convolution of the responsivity of the optical detector array and the transmission spectrum of the one or more optical filters has a first peak in mid-wave infrared spectral region between 3-4 microns corresponding to a first absorption peak of methane and a second peak in a long-wave infrared spectral region between 6-8 microns corresponding to a second absorption peak of methane.

Provided are a Raman signal measuring method and apparatus which use a difference in a time scale between Raman scattered light and fluorescence. Thus, after exciting light is incident upon a target object, light scattered from the target object may be detected before the target object generates fluorescence in response to the exciting light. As a result, a Raman signal in which background fluorescence is reduced may be obtained.

An optical emission spectroscopy (OES) calibration system includes a chamber, an adapter, an OES device, a calibration device, and a spectrometer. The chamber includes a viewport. The adapter is fastened to the viewport, and includes a first beam splitter and a second beam splitter. The OES device detects plasma light generated in the chamber and transmitted through the adapter and generates OES data based on the detected plasma light. The calibration device includes a light source, and generates correction data for compensating for deviations in the OES data. The spectrometer detects light emitted from the light source and split by the first beam splitter or the second beam splitter. Each of the OES device, the calibration device, and the spectrometer is fastened to the adapter through an optical cable, and the calibration device generates the correction data using an intensity of light detected by the spectrometer.

A method includes directing a first plurality of probe laser pulses through a sample, dividing each of the first plurality of probe laser pulses to generate a first interferogram, and generating first image data reproducible as a first phase image of the sample. A plurality of pump laser bursts are directed onto the sample to heat the sample. A second plurality of probe laser pulses are directed through the sample at a predetermined time delay. Each of the second plurality of probe laser pulses are divided to generate a second interferogram. Second image data is generated that is reproducible as a second phase image of the sample. A transient phase shift is determined in the second phase image relative to the first phase image. A vibrational spectroscopy property is determined of the sample based on the transient phase shift, thereby allowing an identification of chemical bond information of within the sample.

In one embodiment, 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 an optical focal plane array (FPA) unit. 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. Said optical system and said processing unit can be contained together in a data acquisition and processing module configured to be worn or carried by a person.

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.

A method includes directing a first plurality of probe laser pulses through a sample, dividing each of the first plurality of probe laser pulses to generate a first interferogram, and generating first image data reproducible as a first phase image of the sample. A plurality of pump laser bursts are directed onto the sample to heat the sample. A second plurality of probe laser pulses are directed through the sample at a predetermined time delay. Each of the second plurality of probe laser pulses are divided to generate a second interferogram. Second image data is generated that is reproducible as a second phase image of the sample. A transient phase shift is determined in the second phase image relative to the first phase image. A vibrational spectroscopy property is determined of the sample based on the transient phase shift, thereby allowing an identification of chemical bond information of within the sample.

An optical emission spectroscopy (OES) calibration system includes a chamber, an adapter, an OES device, a calibration device, and a spectrometer. The chamber includes a viewport. The adapter is fastened to the viewport, and includes a first beam splitter and a second beam splitter. The OES device detects plasma light generated in the chamber and transmitted through the adapter and generates OES data based on the detected plasma light. The calibration device includes a light source, and generates correction data for compensating for deviations in the OES data. The spectrometer detects light emitted from the light source and split by the first beam splitter or the second beam splitter. Each of the OES device, the calibration device, and the spectrometer is fastened to the adapter through an optical cable, and the calibration device generates the correction data using an intensity of light detected by the spectrometer.