Method and system for combined Raman and LIBS detection

• US 7,999,928 B2
• Filed: 01/23/2007
• Issued: 08/16/2011
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Chemimage Corporation
• Original Assignee: Chemimage Corporation
• Inventors: Nelson, Matthew, Treado, Patrick J., Beckstead, Jeffrey
• Primary Examiner(s): Toatley; Gregory J
• Assistant Examiner(s): ALLI, IYABO
• Application Number:
  US11/656,393
• Publication Number:
  US 20100271629A1
• Time in Patent Office: 1,666 Days
• Field of Search: 356/73, 356/73.1, 356/445, 356/446, 356/451, 356/301
• US Class Current: 356/73
• 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 21/65 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

Abstract

In one embodiment, the disclosure relates to a method for interrogating a sample by: illuminating a first region of the sample with a first illumination pattern to obtain a plurality of first sample photons; illuminating a second region of the sample with a second illumination pattern to obtain a plurality of second sample photons; processing the plurality of first sample photons to obtain a characteristic atomic emission of the first region and processing the plurality of second sample photons to obtain a Raman spectrum; and identifying the sample through at least one of the characteristic atomic emission of the first region or the Raman spectrum of the second region of the sample.

Claims

1. A method for interrogating a sample, comprising:

illuminating a first region of the sample with a first illumination pattern to obtain a plurality of first sample photons;

illuminating a second region of the sample with a second illumination pattern to obtain a plurality of second sample photons;

filtering the plurality of second sample photons through an electronically controlled tunable filter;

processing the plurality of first sample photons to obtain a characteristic atomic emission of the first region and processing the plurality of second sample photons to obtain a Raman spectrum; and

identifying the sample through at least one of the characteristic atomic emission of the first region or the Raman spectrum of the second region of the sample.

2. The method of claim 1, wherein the first illumination pattern defines one of a circle, a square, a rectangle or an ellipse.

3. The method of claim 1, wherein the second illumination pattern defines one of a circle, a square, a rectangle, an ellipse or an annulus.

4. The method of claim 1, wherein the first region and the second region partially overlap.

5. The method of claim 1, wherein the step of illuminating the first region further comprises illuminating the second region with laser energy sufficient for Raman spectroscopy.

6. The method of claim 1, wherein the step of illuminating the second region further comprises illuminating the first region with laser energy sufficient for atomic spectroscopy or with laser energy sufficient for induced breakdown spectroscopy.

7. The method of claim 1, wherein the steps of illuminating the first region and illuminating the second region are implemented sequentially.

8. The method of claim 1, wherein the steps of illuminating the first region and illuminating the second region are implemented substantially simultaneously.

28. The method of claim 1 further comprising the step of obtaining a spatially accurate wavelength resolved image of the second region.

9. A method for interrogation of a sample, comprising:

(a) identifying a first region and a second region of the sample;

(b) obtaining a spatially accurate wavelength resolved image of the second region of the sample, wherein said obtaining comprises;

illuminating the second region of the sample to obtain a plurality of sample photons from said second region, and

filtering the plurality of sample photons from said second region though an electronically controlled tunable filter; and

(c) identifying a constituent of the first region by analyzing a characteristic atomic-emission from the first region.

10. The method of claim 9, further comprising:

(d) repeating steps (a)-(c) for an alternative first region and an alternative second region of the sample.

11. The method of claim 9, wherein the first region and the second region overlap.

12. The method of claim 9, wherein the first region and the second region do not overlap.

13. The method of claim 9, wherein step (c) further comprises:

(c)(1) illuminating the sample to produce a plurality of laser induced break down photons; and

(c)(2) collecting the plurality of photons.

14. The method of claim 9, wherein step (b) further comprises:

(b)(1) illuminating the sample to produce a plurality of sample-scattered photons;

(b)(2) collecting the plurality of sample-scattered photons; and

(b)(3) forming a Raman image of the second region from the collected photons.

15. The method of claim 9, further comprising implementing steps (b) and (c) substantially simultaneously.

16. The method of claim 9, further comprising implementing steps (b) and (c) sequentially.

17. The method of claim 9, further comprising obtaining a spatially accurate wavelength resolved image of the first region of the sample.

29. The method of claim 14 further comprising the step of filtering the plurality of sample-scattered photons through an electronically controlled tunable filter.

18. An identification system comprising:

a first illumination source for providing a first plurality of illumination photons to a first region of a sample to thereby form a first plurality of sample photons, and a second illumination source for providing a second plurality of illumination photons to a second region of the sample to thereby form a second plurality of sample photons;

an electronically controlled tunable filter for filtering at least one of said first plurality of sample photons and said second plurality of sample photons;

a collector for receiving said first and second plurality of sample photons and providing first and second signals respectively therefrom, wherein said first plurality of photons is representative of a Raman spectrum for the sample and said second plurality of photons is representative of a characteristic atomic emission of the sample;

a processor for processing said first and second signals; and

a display for displaying at least one of a chemical identification or a spectral representation of the first or the second regions of the sample.

19. The system of claim 18, wherein the identification system is a handheld device.

20. The system of claim 18, wherein the first plurality of photons have an energy level sufficient for Raman spectroscopy.

21. The system of claim 18, wherein the second plurality of photons have an energy level sufficient for laser induced breakdown spectroscopy.

22. The system of claim 18, wherein the identification system substantially simultaneously illuminates the first and the second regions of the sample.

23. The system of claim 18, wherein the identification system sequentially illuminates the first and the second regions of the sample.

24. The system of claim 18, wherein the collector further comprises an optical collection train and a detection system.

25. The system of claim 24, wherein the detection system is one of a charge-coupled device or a CMOS detector.

26. The system of claim 18, wherein the first region and the second region overlap.

27. The system of claim 18, further comprising a fiber array spectral translator for communicating sample photons from the collector to a spectrometer.

30. A method for interrogating a sample, comprising:

illuminating a first region of the sample with a first illumination pattern to obtain a first plurality of sample photons;

illuminating a second region of the sample with a second illumination pattern to obtain a second plurality of sample photons;

passing at least one of the first plurality of sample photons and the second plurality of sample photons through a fiber array spectral translator;

passing at least one of the first plurality of sample photons and the second plurality of sample photons through a tunable filter;

processing the first plurality of sample photons to obtain a characteristic atomic emission of the first region and processing the plurality of sample photons to obtain a Raman spectrum; and

identifying the sample though at least one of the characteristic atomic emission of the first region or the Raman spectrum of the second region of the sample.

31. A method for interrogation of a sample, comprising:

(a) identifying a first region of the sample and a second region of the sample;

(b) obtaining a spatially accurate wavelength resolved image of the second region of the sample, wherein said obtaining comprises passing a plurality of sample photons from said second region through an electronically tunable filter; and

(c) identifying a constituent of the first region by analyzing a characteristic atomic-emission from the first region.

32. A method for interrogation of a sample, comprising:

(a) identifying a first region of the sample and a second region of the sample;

(b) obtaining a spatially accurate wavelength resolved image of the second region of the sample, wherein said obtaining comprises

passing a plurality of sample photons from said second region through a fiber array spectral translator, and

passing the plurality of sample photons from said second region through a tunable filter; and

(c) identifying a constituent of the first region by analyzing a characteristic atomic-emission from the first region.

33. An identification system comprising:

a first illumination source for providing a first plurality of illumination photons to a first region of a sample to thereby form a first plurality of sample photons, and a second illumination source for providing a second plurality of photons to a second region of the sample to thereby form a second plurality of sample photons;

a fiber array spectral translator for passing at least one of said first plurality of sample photons and said second plurality of sample photons to a collector;

a tunable filter for passing at least one of said first plurality of sample photons and said second plurality of sample photons;

said collector for receiving said first plurality of sample photons and said second plurality of sample photons and providing first and second signals respectively therefrom, wherein said first plurality of sample photons is representative of a Raman spectrum for the sample and said second plurality of sample photons is representative of a characteristic atomic emission of the sample;

a processor for processing said first and second signals; and

a display for displaying at least one of chemical identification or a spectral representation of the first or the second regions of the sample.