A variable wavelength optical filter module according to the present invention includes a package, a variable wavelength optical filter, and a detector. The package includes a reflection part (reflecting faces) in the inside of the package. The variable wavelength optical filter is disposed in the inside of the package and includes a first reflecting plate and a second reflecting plate facing each other, with a clearance between the first reflecting plate and the second reflecting plate being variable. The detector is disposed in the inside of the package and detects a ray of light having passed through the variable wavelength optical filter. Then, the variable wavelength optical filter and the detector are disposed on the opposite side to the reflection part (reflecting faces). The ray of the light incident into the inside of the package via the variable wavelength optical filter enters the detector via the reflection part (reflecting faces).

According to an aspect, there is provided a spectrometer comprising a first and second enclosed volumes. The second enclosed volume is formed by an absorption cell for containing a sample gas. The first enclosed volume of the spectrometer comprises an interferometer with a source of electromagnetic radiation, a first focusing mirror adapted to focus electromagnetic radiation received from the interferometer to the absorption cell, a second focusing mirror adapted to focus electromagnetic radiation received from the absorption cell and a detector adapted to detect electromagnetic radiation focused by the second focusing mirror. Moreover, the spectrometer comprises a main frame plate on which elements in the first enclosed volume are mounted and which is fixed to the absorption cell arranged on an opposing side of the main frame plate.

This invention discloses a compact laser induced breakdown spectroscopy (LIBS) apparatus suitable for field operations. The LIBS apparatus comprises a Q-switched laser with laser pulse energy between several tens and several thousands of micro joules (μJ), which is significantly lower than that of traditional LIBS lasers. The spectrograph of the LIBS apparatus employs a dual CCD (charge coupled device) design, which maintains compact size and in the meantime offers large spectral coverage and high spectral resolution.

Apparatus and methods for acquiring a Raman spectral map of a sample including a material species. The apparatus includes: a pulsed illumination source providing pulsed illumination radiation for exciting the sample and producing scattered radiation; a microscope objective focusing the pulsed illumination radiation onto a region of the sample corresponding to a data point of the map, and collecting emitted radiation from the region; a translation stage translating the sample relative to the microscope objective in at least two directions; a spectral filter spectrally filtering the emitted radiation collected by the objective to obtain a filtered portion of radiation corresponding to a characteristic Raman spectral feature of the material species; a detector receiving the filtered portion and providing output electrical pulses indicative thereof; and readout electronics applying a time gate to the output electrical pulses to distinguish detection events corresponding to the Raman scattered radiation from events associated with photoluminescence.

The present invention discloses an infrared image-spectrum associated intelligent detection method and apparatus, including: first searching for targets in a field of view (FOV), and performing image-spectrum associated intelligent identification sequentially on the searched targets, that is, first performing infrared image target identification on each target, and if a detection identification rate is greater than a set threshold, outputting an identification result and storing target image data; otherwise, acquiring an infrared spectrum of the target, and performing target identification based on infrared spectrum features. The present invention further discloses an apparatus for performing target detection using the above method, and the apparatus mainly includes a two-dimensional scanning mirror, a multiband infrared optical module, a long-wave infrared (LWIR) imaging unit, a broadband infrared spectrum measuring unit, and a processing and control unit. The method and apparatus of the present invention are improvements and enhancements of the conventional infrared target detection method and device, and may be used for infrared image detection, infrared image-spectrum associated detection of the target and infrared spectrum collection of the target. Compared with the conventional infrared detection device, the present invention has a higher performance cost ratio, and can significantly improve the detection identification rate of the target.

A method for determining a correcting quantity function k.sub.F(x, y) for calibrating an FTIR measurement arrangement with an IR detector. The IR detector includes a plurality of sensor elements, which are each located at a position (x, y), and the method includes: (a) recording interferograms IFG.sub.Rxy of a reference sample using the sensor elements of the IR detector, (b) calculating spectra R.sub.xy of the reference sample by Fourier transforming the interferograms of the reference sample for at least four sensor elements, (c) calculating correcting quantities k.sub.xy by comparing each spectrum R.sub.xy of the reference sample calculated in step b) with a reference data set of the reference sample, and (d) determining the correcting quantity function k.sub.F(x, y) using the correcting quantities k.sub.xy calculated in step c). This permits frequency shifts that occur in FTIR spectrometers with extensive detectors to be effectively corrected regardless of the position of the sensor element.

A method for enhancement of spontaneous Raman scattering (SRS) from gases comprising a multimode blue laser diode which receives feedback from a near concentric bidirectional multipass cavity in such a way as to generate a circulating power of order 100 W for a sample volume of 10 mm.sup.3. The feedback, provided via a volume Bragg grating, reduces the laser bandwidth to 4 cm.sup.−1. Spectra of spontaneous Raman scattering from ambient atmospheric air, detected collinearly with the pump, were recorded with a limit of detection below 1 part-per-million.

A spectrally-shaped source includes a source that generates a round beam. An optical element transforms the round beam to a rectangular beam. An image forming dispersive device angularly disperses wavelengths and images the rectangular beam at a modulation plane. A pixelated SLM is illuminated by the dispersed wavelengths of the rectangular beam such that each column of illuminated pixels is illuminated by a different wavelength. Toroidal optics projects light directed from the SLM to an output plane and focuses the angularly dispersed wavelengths of the beam so that a selected portion of the optical beam is reflected toward the toroidal optic by the SLM. A controller instructs the pixelated SLM to selectively reflect the portion of the optical beam toward the toroidal optic and to selectively reflect another portion of the beam away from the toroidal optic so as to provide a desired spectral shape.

An optical module 1 includes: a mirror unit 2 including a base 21, a movable mirror 22, and a fixed mirror 16; a beam splitter unit 3 that is disposed on one side of the mirror unit 2 in a Z-axis direction; a light incident unit 4 that causes measurement light L0 to be incident to the beam splitter unit 3; a first light detector 6 that is disposed on the one side of the beam splitter unit 3 in the Z-axis direction, and detects interference light L1 of measurement light which is emitted from the beam splitter unit 3; a support 9 to which the mirror unit 2 is attached; a first support structure 11 that supports the beam splitter unit 3; and a second support structure 12 that is attached to the support 9 and supports the first light detector 6.

An optical system includes a splitting optic configured to receive a light beam from a light source and form a set of light bands radiating from the optical system at predetermined angles relative to illuminate a scene. The optical system further includes a lens configured to project a field of view of the scene into a two-dimensional format. The optical system further includes an optical sensor arranged offset from the central axis of the lens to capture a segment of the field of view projected by the lens.