System and method for combined raman and LIBS detection with targeting

• US 8,547,540 B2
• Filed: 08/15/2011
• Issued: 10/01/2013
• Est. Priority Date: 07/14/2005
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Beckstead, Jeffrey, Treado, Patrick, Nelson, Matthew
• Primary Examiner(s): Toatley, Gregory J
• Assistant Examiner(s): ALLI, IYABO
• Application Number:
  US13/209,670
• Publication Number:
  US 20120062874A1
• Time in Patent Office: 778 Days
• Field of Search: 356/73, 356/73.1, 356/445, 356/446, 356/451, 356/301
• US Class Current: 356/73.1
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/28 Investigating the spectrum using colour filters G01J3/51
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01J 3/443 Emission spectrometry
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/718 Laser microanalysis, i.e. with formation of sample plasma
• CPC Class Codes: G01N 2201/0221 Portable; cableless; compact; hand-held
• CPC Class Codes: G01N 2201/08 Optical fibres; light guides

Abstract

A system and method for locating and identifying unknown samples. A targeting mode may be utilized to scan regions of interest for potential unknown materials. This targeting mode may interrogate regions of interest using SWIR and/or fluorescence spectroscopic and imaging techniques. Unknown samples detected in regions of interest may be further interrogated using a combination of Raman and LIBS techniques to identify the unknown samples. Structured illumination may be used to interrogate an unknown sample. Data sets generated during interrogation may be compared to a reference database comprising a plurality of reference data sets, each associated with a known material. The system and method may be used to identify a variety of materials including: biological, chemical, explosive, hazardous, concealment, and non-hazardous materials.

Claims

1. A method comprising:

illuminating a region of interest to thereby generate a first plurality of interacted photons;

filtering said first plurality of interacted photons;

detecting said first plurality of interacted photons to thereby generate a test data set representative of said region of interest;

analyzing said test data set to thereby identify a unknown sample within said region of interest;

illuminating a first portion of said unknown sample to thereby generate a second plurality of interacted photons;

illuminating a second portion of said unknown sample to thereby generate a third plurality of interacted photons;

filtering at least one of said second plurality of interacted photons and said third plurality of interacted photons;

detecting said second plurality of interacted photons to thereby generate a LIBS data set representative of said unknown sample;

detecting said third plurality of interacted photons to thereby generate a Raman data set representative of said unknown sample; and

analyzing at least one of said LIBS data set and said Raman data set to thereby identify said unknown sample.

2. The method of claim 1 wherein said test data set comprises a SWIR data set.

3. The method of claim 2 wherein said SWIR data set comprises at least one hyperspectral SWIR image.

4. The method of claim 2 wherein said SWIR data set comprises at least one of:

a spatially accurate wavelength resolved SWIR image, a SWIR spectrum, and combinations thereof.

5. The method of claim 1 wherein said test data set comprises a fluorescence data set.

6. The method of claim 5 wherein said fluorescence data set comprises at least one hyperspectral fluorescence image.

7. The method of claim 5 wherein said fluorescence data set comprises at least one of:

a spatially accurate wavelength resolved fluorescence image, a fluorescence spectrum, and combinations thereof.

8. The method of claim 1 wherein said first portion of said unknown sample is illuminated using a first illumination pattern.

9. The method of claim 8 wherein said first illumination pattern is selected from the group consisting of:

a circle, a square, a rectangle, an ellipse, an annulus, and combinations thereof.

10. The method of claim 1 wherein said second portion of said unknown sample is illuminated using a second illumination pattern.

11. The method of claim 10 wherein said second illumination pattern comprises at least one of:

a circle, a square, a rectangle, and ellipse, an annulus, and combinations thereof.

12. The method of claim 1 wherein said filtering of at least one of said first plurality of interacted photons, said second plurality of interacted photons, and said third plurality of interacted photons is achieved using at least one of:

a tunable filter, a fixed filter, a dielectric filter, and combinations thereof.

13. The method of claim 12 wherein said filtering is achieved using a tunable filter selected from the group consisting of:

a liquid crystal tunable filter, a multi-conjugate 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, a Fabry Perot liquid crystal tunable filter, and combinations thereof.

14. The method of claim 1 wherein said analyzing of said LIBS data set and said Raman data set further comprises applying at least one fusion algorithm to thereby generate a fused data set representative of said unknown sample.

15. The method of claim 14 further comprising analyzing said fused data set to thereby identify said unknown sample.

16. The method of claim 1 wherein said LIBS data set comprises at least one hyperspectral LIBS image.

17. The method of claim 1 wherein said LIBS data set comprises at least one of:

a spatially accurate wavelength resolved LIBS image, a LIBS spectrum, and combinations thereof.

18. The method of claim 1 wherein said Raman data set comprises at least one hyperspectral Raman image.

19. The method of claim 1 wherein said Raman data set comprises at least one of:

a spatially accurate wavelength resolved Raman image, a Raman spectrum, and combinations thereof.

20. The method of claim 1 wherein said first portion of said unknown sample and said second portion of said unknown sample are illuminated in one of the following modalities:

sequentially, simultaneously, and combinations thereof.

21. The method of claim 1 wherein said first portion of said unknown sample and said second portion of said unknown sample at least partially overlap.

22. The method of claim 1 wherein at least one of said first portion of said unknown sample and said second portion of said unknown sample are illuminated using a laser illumination source.

23. The method of claim 1 wherein said region of interest is illuminated using at least one of:

a passive illumination source, a laser light source, a broadband light source, an ambient light source, and combinations thereof.

24. The method of claim 1 wherein at least one of said first portion of said unknown sample and said second portion of said unknown sample is illuminated using at least one of:

a passive illumination source, a laser light source, a broadband light source, an ambient light source, and combinations thereof.

25. The method of claim 1 wherein said first plurality of interacted photons, said second plurality of interacted photons, and said third plurality of interacted photons are detected using a portable device.

26. The method of claim 25 further wherein at least one of said region of interest, said first portion of said unknown sample, said second portion of said unknown sample, and combinations thereof are illuminated using said portable device.

27. The method of claim 1 further comprising passing at least one of said first plurality of interacted photons, said second plurality of interacted photons, said third plurality of interacted photons, and combinations thereof through a fiber array spectral translator device.

28. The method of claim 1 wherein at least one of said first plurality of interacted photons, said second plurality of interacted photons, said third plurality of interacted photons, and combinations thereof, are detected using a focal plane array detector.

29. The method of claim 28 wherein said focal plane array detector is selected from the group consisting of:

an InGaAs detector, a CMOS detector, an ICCD detector, a CCD detector, and combinations thereof.

30. The method of claim 1 wherein said analyzing of said test data set further comprises comparing said test data set to at least one reference data set using a chemometric technique.

31. The method of claim 1 wherein said analyzing of at least one of said LIBS data set and said Raman data set further comprises comparing at least one of said LIBS data set and said Raman data set to at least one reference data set using a chemometric technique.

32. The method of claim 1 wherein identifying said unknown sample further comprises identifying said unknown sample as at least one of:

a biological material, a chemical material, an explosive material, a hazardous material, a concealment material, a non-hazardous material, and combinations thereof.