Advanced optics for rapidly patterned laser profiles in analytical spectrometry

• US 20050242277A1
• Filed: 02/11/2005
• Published: 11/03/2005
• Est. Priority Date: 02/12/2004
• Status: Active Grant

• Current Assignee: Texas A&M University System
• Original Assignee: Texas A&M University System
• Inventors: Russell, David H., McLean, John A.
• Granted Patent: US 7,282,706 B2
• Time in Patent Office: Days
• US Class Current: 250/282
• CPC Class Codes: H01J 49/164 Laser desorption/ionisation, e.g. matrix-assisted laser desorption/ionisation [MALDI] sample holders H01J49/0418

Abstract

The present invention is directed to a novel arrangement of optical devices for the rapid patterning of laser profiles used for desorption and/or ionization sources in analytical mass spectrometry. Specifically, the new optical arrangement provides for a user-defined laser pattern at the sample target that can be quickly changed (on a microsecond timescale) to different dimensions (or shapes) for subsequent laser firings.

Claims

1. A method for inspecting a sample comprising the steps of:

providing a wavefront of photons from a photon source;

transforming the wavefront of photons into a uniform intensity profile;

selectively varying the spatial distribution of photons within said uniform intensity profile to construct a photon pattern;

focusing said photon pattern on at least a portion of a sample; and

,

desorbing, and optionally ionizing, at least a portion of said sample.

2. The method of claim 1, further comprising mass spectrometric analysis of said sample after said step of desorbing.

3. The method of claim 1, fuirther comprising ion mobility spectrometric analysis of said sample after said step of desorbing.

4. The method of claim 1, wherein said step of providing comprises generating photons from a radiation source selected from the group consisting of a laser, a Nernst glower, a globar, an arc discharge, a plasma discharge, a hollow cathode lamp, a synchrotron, a flashlamp, a resistively heated source, and any combination thereof.

5. The method of claim 1, wherein said step of transforming comprises using one or more refractive homogenizer optical elements.

6. The method of claim 5, wherein said one or more refractive homogenizer optical elements is selected from the group consisting of a prism homogenizer, a crossed-cylindrical lens array, an off-axis cylindrical lens, and any combination thereof.

7. The method of claim 1, wherein said step of transforming comprises using one or more non-refractive homogenizer optical elements.

8. The method of claim 7, wherein said one or more non-refractive homogenizer optical elements is selected from the group consisting of a reflective non-refractive optical element, a diffractive non-refractive optical element, and any combination thereof.

9. The method of claim 1, wherein said step of transforming comprises using a waveguide.

10. The method of claim 9, wherein said waveguide is a fiber optic.

11. The method of claim 1, wherein said step of selectively varying comprises using a component selected from the group consisting of a digital micro-mirror array, a variable slit, an optical mask, and any combination thereof.

12. The method of claim 1, wherein said sample is biological tissue.

13. The method of claim 12, wherein said biological tissue is plant or animal tissue.

14. The method of claim 1, wherein said sample is a laser microcapture dissection sample.

15. The method of claim 1, wherein said sample is selected from the group consisting of a protein, a nucleotide, a nucleic acid, a deoxynucleic acid, a protein microarray, a nucleotide microarray, a nucleic acid microarray, a deoxynucleic acid microarray, an immobilized biological material, a patterned biological material, and any combination thereof.

16. The method of claim 1, wherein said sample is selected from the group consisting of inorganic samples, semiconductors, ceramics, polymers, composites, metals, alloys, glasses, fibers, and any combination thereof.

17. The method of claim 1, further comprising the step of correcting said spatial distribution for perspective distortion.

18. The method of claim 17, wherein said step of correcting comprises using selected photon patterns for said step of focusing, said selected photon patterns designed to eliminate perspective distortion.

19. The method of claim 17, wherein said step of correcting comprises calibrating for perspective distortion using an image captured by a CCD array.

20. An apparatus for inspecting a sample, said apparatus comprising:

a source for providing a wavefront of photons, said source having sufficient power to desorb, and optionally ionize, at least a portion of said sample;

means for transforming the wavefront of photons into a uniform intensity profile, said means for transforming being fluidly coupled to said source;

means for selectively varying the spatial distribution of photons within said uniform intensity profile to construct a photon pattern, said means for selectively varying being fluidly coupled to said means for transforming; and

,

means for focusing said photon pattern onto said sample, said means for focusing being fluidly coupled to said means for selectively varying.

21. The apparatus of claim 20, further comprising a mass spectrometer fluidly coupled to said sample such that at least a portion of material desorbed and optionally ionized from said sample enters said mass spectrometer.

22. The apparatus of claim 20, further comprising an ion mobility spectrometer fluidly coupled to said sample such that at least a portion of material desorbed and optionally ionized from said sample enters said ion mobility spectrometer.

23. The apparatus of claim 20, wherein said source is selected from the group consisting of a laser, a Nernst glower, a globar, an arc discharge, a plasma discharge, a hollow cathode lamp, a synchrotron, a flashlamp, a resistively heated source, and any combination thereof.

24. The apparatus of claim 20, wherein said means for transforming comprises one or more refractive homogenizer optical elements.

25. The apparatus of claim 24, wherein said one or more refractive homogenizer optical elements is selected from the group consisting of a prism homogenizer, a crossed-cylindrical lens array, an off-axis cylindrical lens, and any combination thereof.

26. The apparatus of claim 20, wherein said means for transforming comprises one or more non-refractive homogenizer optical elements.

27. The apparatus of claim 26, wherein said one or more non-refractive homogenizer optical elements is selected from the group consisting of a reflective homogenizer optical element, a diffractive homogenizer optical element, and any combination thereof.

28. The apparatus of claim 20, wherein said means for selectively varying is selected from the group consisting of a digital micro-mirror array, a variable slit, an optical mask, and any combination thereof.

29. The apparatus of claim 28, wherein said means for selectively varying is a digital micro-mirror array.

30. A method for inspecting a sample comprising the steps of:

providing a plurality of wavefronts of photons from a plurality of photon sources;

transforming said plurality of wavefronts into a plurality of uniform intensity profiles;

selectively varying the spatial distribution of photons within said uniform intensity profiles to construct a plurality of photon patterns;

focusing said plurality photon patterns onto a sample; and

,

desorbing, and optionally ionizing, at least a portion of said sample to form a plurality of packets of desorbed and optionally ionized material.

31. The method of claim 30, further comprising the step of mass spectrometric analysis of said sample after said step of desorbing, said step of mass spectrometric analysis being performed with one or more mass spectrometers.

32. The method of claim 30, further comprising the step of ion mobility spectrometric analysis of said sample after said step of desorbing, said step of ion mobility spectrometric analysis being performed with one or more ion mobility spectrometers.

33. The method of claim 30, wherein said step of providing comprises generating photons from a radiation source selected from the group consisting of a laser, a Nernst glower, a globar, an arc discharge, a plasma discharge, a hollow cathode lamp, a synchrotron, a flashlamp, a resistively heated source, and any combination thereof.

34. The method of claim 30, wherein said step of transforming comprises using one or more refractive homogenizer optical elements.

35. The method of claim 34, wherein said one or more refractive homogenizer optical elements is selected from the group consisting of a prism homogenizer, a crossed-cylindrical lens array, an off-axis cylindrical lens, and any combination thereof.

36. The method of claim 30, wherein said step of transforming comprises using one or more non-refractive homogenizer optical elements.

37. The method of claim 36, wherein said one or more non-refractive homogenizer optical elements is selected from the group consisting of a reflective non-refractive optical element, a diffractive non-refractive optical element, and any combination thereof.

38. The method of claim 30, wherein said step of transforming comprises transforming using a waveguide.

39. The method of claim 38 wherein said waveguide is a fiber optic.

40. The method of claim 30, wherein said step of selectively varying comprises using a component selected from the group consisting of a digital micro-mirror array, a variable slit, an optical mask, and any combination thereof.

41. The method of claim 30, wherein said sample is biological tissue.

42. The method of claim 41, wherein said biological tissue is plant or animal tissue.

43. The method of claim 30, wherein said sample is a laser microcapture dissection sample.

44. The method of claim 30, wherein said sample is selected from the group consisting of a protein, a nucleotide, a nucleic acid, a deoxynucleic acid, a protein microarray, a nucleotide microarray, a nucleic acid microarray, a deoxynucleic acid microarray, an immobilized biological material, a patterned biological material, and any combination thereof.

45. The method of claim 30, wherein said sample is selected from the group consisting of inorganic samples, semiconductors, ceramics, polymers, composites, metals, alloys, glasses, fibers, and any combination thereof.

46. The method of claim 30, further comprising the step of correcting said spatial distribution for perspective distortion.

47. The method of claim 46, wherein said step of correcting comprises using selected photon patterns for said step of focusing, said selected photon patterns designed to eliminate perspective distortion.

48. The method of claim 46, wherein said step of correcting comprises calibrating for perspective distortion using an image captured by a CCD array.

49. The method of claim 30, wherein said plurality of photon patterns are noncongruent photon patterns.

50. A method for inspecting a sample comprising the steps of:

providing a wavefront of photons from a photon source;

transforming the wavefront of photons into a uniform intensity profile;

selectively varying the spatial distribution of photons within said uniform intensity profile to construct a photon pattern;

focusing said photon pattern on at least a portion of a sample;

desorbing, and optionally ionizing, at least a portion of said sample to form a desorbed sample; and

,

thereafter performing mass spectrometry, or ion mobility spectrometry, or a combination of ion mobility spectrometry and mass spectrometry on at least a portion of said desorbed and optionally ionized sample.