Method and apparatus for analyzing a test material by inducing and detecting light-matter interactions

• US 6,370,406 B1
• Filed: 08/20/1999
• Issued: 04/09/2002
• Est. Priority Date: 11/20/1995
• Status: Expired due to Term

• Current Assignee: Cirrex Systems, LLC
• Original Assignee: Cirrex Corp. (Cirrex Systems, LLC)
• Inventors: Wach, Michael L., Marple, Eric T.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/378,659
• Time in Patent Office: 963 Days
• Field of Search: 600/310, 600/322, 600/341, 600/342, 356/39, 356/300, 356/301, 356/302, 356/303, 356/311, 356/317
• US Class Current: 600/310
• CPC Class Codes: G01N 2021/656 Raman microprobe
• CPC Class Codes: G01N 21/474 Details of optical heads therefor, e.g. using optical fibres
• CPC Class Codes: G01N 21/65 Raman scattering
• CPC Class Codes: G01N 21/7703 using reagent-clad optical fibres or optical waveguides using measurement of total internal reflection or attenuated total reflection G01N21/552; optical fibres or waveguides per se G02B
• CPC Class Codes: G02B 6/02052 comprising optical elements other than gratings, e.g. filters comprising gratings G02B6/02057
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/241 Light guide terminations
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/29362 Serial cascade of filters or filtering operations, e.g. for a large number of channels
• CPC Class Codes: G02B 6/29364 Cascading by a light guide path between filters or filtering operations, e.g. fibre interconnected single filter modules
• CPC Class Codes: G02B 6/29368 Light guide comprising the filter, e.g. filter deposited on a fibre end G02B6/29359 takes precedence
• CPC Class Codes: G02B 6/29388 for lighting or use with non-coherent light
• CPC Class Codes: G02B 6/4203 Optical features

Abstract

A method and apparatus for analyzing a test material by inducing and detecting light-matter interactions. Particles of matter are introduced into a volume bounded by reflective surfaces wherein light of discrete frequencies can set up a standing wave mode of low loss. Light transported over a waveguide is introduced to induce a state change in the particles of matter and to cause the release of quantitized energy from the matter. A portion of the quantitized energy is captured and transported over a waveguide to a detector. The detector records a portion of the quantitized energy. Characteristics of the particles of matter may then be determined based upon the recorded portion of the quantitized energy.

Claims

1. A method for analyzing particles of matter, comprising the steps of:

introducing said particles of matter into a volume partially bounded by reflective surfaces wherein light of discrete frequencies can set up at least one standing wave mode of low loss, a portion of the volume being surrounded by a totally internally reflective interface;

exciting said particles from a first state to a second state with light transported over a waveguide so that said particles thereby release quantitized energy;

capturing a portion of said quantitized energy as captured energy;

transporting a portion of said captured energy over a waveguide to a detector;

recording a portion of said captured energy with said detector; and

inferring characteristics of said particles of matter based upon said recorded portion of said captured energy.

2. The method of claim 1 wherein said second state is semi-stable.

3. The method of claim 1 wherein said second state is a virtual state.

4. The method of claim 1 wherein said release of quantitized energy is stimulated.

5. The method of claim 1 wherein said release of quantitized energy is spontaneous.

6. The method of claim 1 wherein said state change is associated with Raman light-matter interactions and wherein said step of inferring step is based upon Raman spectroscopy.

7. The method of claim 1 wherein said inferring step comprises deriving characteristics of said particles of matter from elastic light-matter interactions occurring within said volume.

8. The method of claim 1 wherein said inferring step comprises deriving characteristics of said particles of matter from inelastic light-matter interactions occurring within said volume.

9. The method of claim 1 wherein said particles of matter comprises human tissue.

10. The method of claim 1 wherein said particles of matter comprises a cerebrospinal fluid constituent.

11. The method of claim 1 wherein said particles of matter comprises amniotic fluid constituent.

12. The method of claim 1 wherein said particles of matter comprises at least one blood constituent.

13. The method of claim 12 further comprising the step of ascertaining blood chemistry based upon said inferred characteristics of said particles of matter.

14. The method of claim 1 further comprising the step of inserting a portion of said volume into an investigative medium.

15. The method of claim 14 wherein said volume is inserted into a human being.

16. The method of claim 15 wherein said volume is inserted into a vascular lumen.

17. The method of claim 1 wherein a component of said particles of matter is excluded from introduction into said volume by a porous matrix.

18. The method of claim 14 wherein said investigative medium comprises aqueous material.

19. The method of claim 1 wherein said particles of matter is an environmental material.

20. The method of claim 1 further comprising the step of ascertaining environmental contamination based upon said inferred characteristics of said particles of matter.

21. The method of claim 1 wherein said particles of matter comprises a ground water component.

22. The method of claim 1 further comprising the step of introducing a reference material into the volume.

23. The method of claim 1 further comprising the step of introducing a signal enhancement material into the volume.

24. The method of claim 23 wherein said signal enhancement material amplifies said quantitized energy by surface enhancement.

25. The method of claim 1 wherein an additive accompanies said particles of matter within said volume,

and wherein said additive is operable to increase an aggregate refractive index of said particles of matter.

26. The method of claim 1 wherein said particles of matter comprise molecules.

27. The method of claim 1 wherein said reflective surfaces comprise two facing mirrors.

28. The method of claim 1 wherein said reflective surfaces derive reflectivity from a thin-film structure.

29. The method of claim 28 wherein said thin-film structure has packing density greater than 99% in a thin film layer.

30. The method of claim 1 wherein a portion of said light is diverted into a light trap.

31. The method of claim 1 wherein said light is segregated from a light source using a filter.

32. The method of claim 1 wherein said light comprises laser light.

33. The method of claim 1 wherein said volume comprises an etalon.

34. The method of claim 1 wherein said volume is surrounded in part by a material having a lower refractive index than said particles of matter.

35. The method of claim 1 wherein said particles of matter enter said volume thorough a permeable matrix.

36. The method of claim 35 wherein said permeable matrix comprises a filter.

37. The method of claim 1 wherein said volume is bounded in part by a polymer element.

38. The method of claim 37 wherein said polymer element is permeable to said particles of matter.

39. The method of claim 37 wherein said polymer element comprises fluorine.

40. The method of claim 1 wherein an isolator is applied to said waveguide.

41. The method of claim 1 further comprising the step of disposing of an assembly including said volume.

42. The method of claim 1 further comprising the step of dispersing a portion of said captured quantitized energy.

43. An apparatus for analyzing a test material by inducing and detecting light-matter interactions comprising:

a distal element comprising a cavity for partially resonating energy from an excitation luminous energy, a portion of the cavity comprising a totally internally reflective interface for waveguiding the excitation luminous energy;

a first carrying means for coupling the excitation luminous energy from a source to said distal element, and

a second carrying means for coupling test luminous energy from said distal element to a detector.

44. The apparatus of claim 43 wherein said distal element comprises:

a first optical port though which a portion of said excitation luminous energy may enter said cavity;

a second optical port through which a portion of said excitation luminous energy may exit said cavity; and

a material port through which a test material may be introduced into said cavity.

45. An apparatus for analyzing material comprising:

a chamber comprising partially reflective surfaces wherein photonic energy of discrete frequencies can set up at least one standing wave mode of low loss, the chamber further comprising totally internally reflective interface for waveguiding the phontonic energy;

a source for generating photonic energy;

an optical detector;

a means for coupling energy between said source and said chamber;

a means for coupling energy between said chamber and said detector;

a means for energizing said chamber with photonic energy; and

an inlet for passing material into said chamber.

46. An apparatus for remote material analysis comprising:

a cavity;

an optical path within said cavity along which luminous energy flows, the optical path comprising partially reflective surfaces wherein luminous energy of discrete frequencies can set up at least one standing wave mode of low loss, the optical path further comprising totally internally reflective interface for waveguiding the luminous energy wherein a first flux is established at a defined cross section of said optical path;

a waveguide connecting said optical path and an optical source so that a second flux greater than said first flux is established at a defined cross section of said waveguide.

47. The optical assembly of claim 46 wherein said first flux is at least five times greater than said second flux.

48. The optical assembly of claim 46 wherein a spatial energy distribution in a cross section of said cavity is contiguous.

49. An apparatus for light-based material characterization of a sample, comprising:

a housing;

a cavity comprising partially reflective surfaces wherein optical energy of discrete frequencies can set up at least one standing wave mode of low loss, the cavity further comprising totally internally reflective interface for waveguiding the optical energy;

means for delivering a first test signal to said cavity and receiving a second test signal from said cavity;

means for resonating optical energy within said cavity;

means for introducing a sample into said cavity; and

means for segregating said first and second test signals.