System and method for safer detection of unknown materials using dual polarized hyperspectral imaging and Raman spectroscopy

• US 8,743,358 B2
• Filed: 03/15/2013
• Issued: 06/03/2014
• Est. Priority Date: 11/10/2011
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Treado, Patrick, Nelson, Matthew, Gardner, Charles
• Primary Examiner(s): Chowdhury, Tarifur
• Assistant Examiner(s): Nur, Abdullahi
• Application Number:
  US13/842,098
• Publication Number:
  US 20140118722A1
• Time in Patent Office: 445 Days
• Field of Search: 356 72- 73, 356/301, 356/326, 356/328
• US Class Current: 356/326
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0221 the fibers defining an entry slit
• CPC Class Codes: G01J 3/0224 using polarising or depolarising elements
• CPC Class Codes: G01J 3/32 Investigating bands of a spectrum in sequence by a single detector
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01N 21/17 Systems in which incident light is modified in accordance with the properties of the material investigated where the material investigated is optically excited causing a change in wavelength of the incident light G01N21/63
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/3581 using far infrared light; using Terahertz radiation
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G02B 21/0092 Polarisation microscopes
• CPC Class Codes: G02B 21/16 adapted for ultraviolet illumination ; Fluorescence microscopes G02B21/0076 takes precedence
• CPC Class Codes: G02B 21/361 Optical details, e.g. image relay to the camera or image sensor G02B21/364 takes precedence; illumination details G02B21/06 and subgroups

Abstract

A first location comprising an unknown material may be scanned using SWIR hyperspectral imaging in a dual polarization configuration. Surveying may also be applied to thereby determine whether or not a human is present. This surveying may be achieved my assessing LWIR data, data acquired from motion sensors, and combinations thereof. If no human is present, a second location may be interrogated using Raman spectroscopic techniques to thereby obtain a Raman data set representative of the region of interest. This Raman data set may be assessed to associate an unknown material with a known material. This assessment may be achieved by comparing the Raman data set to one or more reference data sets in a reference database, where each reference data set is associated with a known material.

Claims

1. A system comprising:

a first subsystem comprising;

a first collection optics configured to collect a first plurality of interacted photons from a first location comprising at least one unknown material, wherein the first plurality of interacted photons comprise optical components in a plurality of polarization alignments,

a first polarization assembly configured to;

receive the first plurality of interacted photons,

separate the first plurality of interacted photons into a first optical component and a second optical component, and

transmit the first optical component with a first polarization alignment and the second optical component with a second polarization alignment,

a first optical filter configured to receive the second optical component and transmit at least a portion of the second optical component having a first wavelength,

a second optical filter configured to receive the second optical component and transmit at least a portion of the second optical component having a second wavelength,

at least one short wave infrared detector configured to detect at least one of the first optical component and the second optical component and generate a SWIR data set representative of the first location;

a second subsystem comprising;

an illumination source configured to illuminate a second location comprising at least one unknown material to generate a second plurality of interacted photons,

a second collection optics configured to collect the second plurality of interacted photons,

a fiber array spectral translator device, wherein the device further comprises a two-dimensional array of optical fibers drawn into a one-dimensional fiber stack so as to effectively convert a two-dimensional field of view into a curvilinear field of view, and wherein the two dimensional array of optical fibers is configured to receive a plurality of photons and transfer the photons out of the fiber array spectral translator device,

a spectrometer comprising an entrance slit coupled to the one-dimensional end of the fiber stack, wherein the spectrometer is configured to generate a plurality of Raman spectra, and

a Raman detector configured to detect the photons from the spectrometer and generate a Raman data set representative of the second location;

a third subsystem comprising;

a third collection optics configured to collect a third plurality of interacted photons from a third location,

a long wave infrared detector configured to detect the third plurality of interacted photons and generate a LWIR data set representative of the third location.

2. The system of claim 1 wherein the first subsystem further comprises a RGB camera configured to generate a RGB video image of at least one of the first location, the second location, and the third location.

3. The system of claim 1 wherein at least one of the first optical filter and the second optical filter further comprise a tunable filter.

4. The system of claim 3 wherein the tunable filter further comprises at least one of:

a multi-conjugate liquid crystal tunable filter, an acousto-optical tunable filter, a Lyot liquid crystal tunable filter, an Evans split-element liquid crystal tunable filter, a Solc liquid crystal tunable filter, a ferroelectric liquid crystal tunable filter, and a Fabry Perot liquid crystal tunable filter.

5. The system of claim 1 wherein at least one SWIR detector further comprises a focal plane array.

6. The system of claim 5 wherein the focal plane array further comprises at least one of:

a InGaAs detector, a CMOS detector, an InSb detector, a MCT detector, an ICCD detector, and a CCD detector.

7. The system of claim 1 wherein a first SWIR detector is configured to detect the first optical component, further comprising a second SWIR detector configured to detect a second optical component.

8. The system of claim 1 wherein at least one of the first collection optics, the second collection optics, and the third collection optics further comprise a telescope optics.

9. The system of claim 1 wherein the Raman detector further comprises a focal plane array.

10. The system of claim 9 wherein the focal plane array further comprises at least one of:

a InGaAs detector, a CMOS detector, an InSb detector, a MCT detector, an ICCD detector, and a CCD detector.

11. The system of claim 1 wherein the LWIR detector further compromises a focal plane array.

12. The system of claim 11 wherein the focal plane array further comprises at least one of:

a InGaAs detector, a CMOS detector, an InSb detector, a MCT detector, an ICCD detector, and a CCD detector.

13. The system of claim 1 further comprising a third optical filter configured to filter the third plurality of interacted photons into a plurality of wavelength bands.

14. The system of claim 1 further comprising a shutter coupled to the illumination source.

15. The system of claim 1 further comprising at least one reference database comprising at least one reference data set, wherein each reference data set is associated with a known material.

16. The system of claim 1 further comprising a processor configured to analyze at least one of the SWIR data set and the Raman data set.

17. The system of claim 1 wherein at least one of the first optics, the second optics, and the third optics further comprises at least one of:

a refractive optic and a reflective optic.

18. A method comprising:

surveying a first location comprising at least one unknown material, wherein surveying comprises;

collecting a first plurality of interacted photons from a first location comprising at least one unknown material, wherein the first plurality of interacted photons comprise optical components in a plurality of polarization alignments,

separating the interacted photons into a first optical component and a second optical component,

transmitting the first optical component to a first optical filter and the second optical component to a second optical filter,

passing the first optical the first optical component through a first optical filter configured to transmit at least a portion of the first optical component having a first wavelength,

passing the second optical component through a second optical filter configured to transmit at least a portion of the second optical component having a second wavelength, and

detecting the first optical component and the second optical component using at least one short wave infrared detector to generate at least a first SWIR data set representative of the first location and a second SWIR data set representative of the first location,

analyzing at least one of the first SWIR data set and the second SWIR data set to identify a second location comprising the unknown material;

targeting the second location, wherein targeting comprises;

illuminating the second location to generate a second plurality of interacted photons using a laser illumination source;

passing the second plurality of interacted photons through a fiber array spectral translator device, and

detecting the second plurality of interacted photons and generating at least one Raman data set representative of the second location, and

analyzing the Raman data set to thereby associate the unknown material with a known material.

19. The method of claim 18 further comprising

collecting a third plurality of interacted photons from a third location comprising the unknown material;

generating at least one LWIR data set representative of a third location; and

analyzing the LWIR data set to determine at least one of;

the presence of a human in the third location and the absence of a human in the third location.

20. The method of claim 19 wherein if the presence of a human is detected in the third location, further comprising stopping laser illumination.

21. The method of claim 19 wherein analyzing the LWIR data set further comprise comparing the data set with at least one reference data set wherein each reference data set is associated with a known material.

22. The method of claim 19 further comprising generating a RGB image of the third location.

23. The method of claim 19 wherein at least a portion of the first location, the second location, and the third location overlap.

24. The method of claim 19 wherein the LWIR data set further comprises a hyperspectral image.

25. The method of claim 19 wherein the LWIR data set further comprises at least one of:

a LWIR spectrum and a spatially accurate wavelength resolved LWIR image.

26. The method of claim 18 wherein the first optical component and the second optical component are detected simultaneously.

27. The method of claim 18 wherein the first optical component and the second optical component are detected sequentially.

28. The method of claim 18 wherein the first SWIR data set and the second SWIR data set are displayed in an overlaid configuration.

29. The method of claim 18 wherein the first SWIR data set and the second SWIR data set are displayed in a non-overlaid configuration.

30. The method of claim 18 wherein analyzing at least one of the SWIR data set and the Raman data set is achieved by comparing the data set with at least one reference data set, wherein each reference data set is associated with a known material.

31. The method of claim 30 wherein the comparison is achieved by applying at least one chemometric technique.

32. The method of claim 18 further comprising generating a RGB image of at least one of:

the first location and the second location.

33. The method of claim 18 wherein at least a portion of the first location and the second location overlap.

34. The method of claim 18 wherein the SWIR data set further comprises a hyperspectral image.

35. The method of claim 18 wherein the SWIR data set further comprises at least one of:

a SWIR spectrum and a spatially accurate wavelength resolved SWIR image.

36. The method of claim 18 wherein the Raman data set further comprises a plurality of spatially resolved Raman spectra.