System and method for optical coherence imaging

• US 20060055936A1
• Filed: 09/12/2005
• Published: 03/16/2006
• Est. Priority Date: 09/10/2004
• Status: Active Grant

• Current Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Original Assignee: The General Hospital Corporation (Mass General Brigham, Inc.)
• Inventors: Bouma, Brett Eugene, Yun, Seok-Hyun, Tearney, Guillermo J., deBoer, Johannes F.
• Granted Patent: US 7,365,859 B2
• Time in Patent Office: Days
• US Class Current: 356/479
• CPC Class Codes: G01B 2290/45 Multiple detectors for detecting interferometer signals
• CPC Class Codes: G01B 2290/70 Using polarization in the interferometer
• CPC Class Codes: G01B 9/02004 using frequency scans
• CPC Class Codes: G01B 9/02014 by using pulsed light
• CPC Class Codes: G01B 9/02044 Imaging in the frequency domain, e.g. by using a spectrometer
• CPC Class Codes: G01B 9/02069 Synchronization of light source or manipulator and detector
• CPC Class Codes: G01B 9/02077 of the object
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B

Abstract

A system and method for imaging of a sample, e.g., biological sample, are provided. In particular, at least one source electro-magnetic radiation forwarded to the sample and a reference may be generated. A plurality of detectors may be used, at least one of the detectors capable of detecting a signal associated with a combination of at least one first electro-magnetic radiation received from the sample and at least one second electro-magnetic radiation received from the reference. At least one particular detector may have a particular electrical integration time, and can receive at least a portion of the signal for a time duration which has a first portion with a first power level greater than a predetermined threshold and a second portion immediately preceding or following the first portion. The second portion may have a second power level that is less than the predetermined threshold, and extends for a time period which may be, e.g., approximately more than 10% of the particular electrical integration time.

Claims

1. A system for imaging at least a portion of a sample, comprising:

a source arrangement generating at least one source electro-magnetic radiation forwarded to the sample and a reference; and

at least one detection arrangement including a plurality of detectors, at least one of the detectors capable of detecting a signal associated with a combination of at least one first electro-magnetic radiation received from the sample and at least one second electro-magnetic radiation received from the reference,

wherein at least one particular detector of the detectors has a particular electrical integration time, wherein the at least one particular detector receives at least a portion of the signal for a time duration which has at least one first portion with at least one first power level greater than a predetermined threshold and at least one second portion immediately preceding or following the at least one first portion, the at least one second portion having at least one second power level less than the predetermined threshold, and wherein the at least one second portion is extended for a time period which is approximately at least 10% of the particular electrical integration time.

2. The system according to claim 1, wherein the signal is at least one of frequency components of the combination.

3. The system according to claim 2, wherein the at least one particular detector receives the at least one of the frequency components.

4. The system according to claim 3, wherein the source arrangement is a pulsed broadband source.

5. The system according to claim 4, wherein the at least one source electro-magnetic radiation generated by the pulsed source is a single pulse per the particular electrical integration time.

6. The system according to claim 5, wherein the pulsed source includes at least one of a Q-switched laser, a cavity-dumped mode-lock laser, and a gain-switched laser.

7. The system according to claim 4, wherein the at least one source electro-magnetic radiation generated by the source arrangement is a burst of radiation that extends for at most approximately 90% of the particular electrical integration time.

8. The system according to claim 7, wherein the burst of radiation includes multiple pulses.

9. The system according to claim 4, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a spectrum with a center wavelength between approximately 700 nanometers and 2000 nanometers.

10. The system according to claim 9, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a spectrum with a spectral width of approximately greater than 1% of the center wavelength.

11. The system according to claim 5, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a pulse width approximately shorter than 1 μ

sec.

12. The system according to claim 4, wherein a duration of the burst of radiation is approximately shorter than 1 μ

sec.

13. The system according to claim 3, wherein the source arrangement includes an optical gating switch.

14. The system according to claim 3, wherein a frequency of the at least one source electro-magnetic radiation varies over time.

15. The system according to claim 14, wherein a mean frequency of the at least one source electro-magnetic radiation changes substantially continuously over time at a tuning speed that is greater than 100 terahertz per millisecond.

16. The system according to claim 14, wherein the mean frequency changes repeatedly with a repetition period that is less than approximately 90% of the particular electrical integration time.

17. The system according to claim 14, wherein the at least one source electro-magnetic radiation generated by the source arrangement has a tuning range with a center wavelength between approximately 700 nanometers and 2000 nanometers.

18. The system according to claim 14, wherein the at least one source electro-magnetic radiation generated by the source arrangement has a tuning range of approximately greater than 1% of the center wavelength.

19. The system according to claim 14, wherein the at least one source electro-magnetic radiation generated by the source arrangement has an instantaneous line width and a tuning range, the instantaneous line width being less than approximately 10% of the tuning range.

20. The system according to claim 14, wherein the source arrangement includes a tunable laser.

21. The system according to claim 14, wherein the source arrangement includes a tunable filter.

22. The system according to claim 14, wherein the source arrangement includes a medium, and wherein the source arrangement generates the at least one source electro-magnetic radiation based on a non-linearity associated with the medium.

23. The system according to claim 14, wherein the frequency varies substantially linearly with time.

24. The system according to claim 14, wherein the frequency varies substantially sinusoidally with time.

25. The system according to claim 3, wherein the detector arrangement further includes an electrical shutter that is adapted to gate a transmission of photoelectrons associated with the combination of the first and second electro-magnetic radiation, wherein a time period for the gating to allow the transmission of the photoelectrons is less than approximately 90% of the particular electrical integration time.

26. The system according to claim 3, wherein the sample is a biological sample.

27. The system according to claim 3, wherein the detection arrangement includes at least one charged-coupled device.

28. The system according to claim 1, wherein the source arrangement is a pulsed broadband source.

29. The system according to claim 1, wherein the detection arrangement includes at least one charged-coupled device.

30. The system according to claim 3, further comprising at least one spectral separating unit which separates spectrum of at least one of the first electro-magnetic radiation, the second electro-magnetic radiation and the combination into the at least one of the frequency components.

31. A method for imaging at least a portion of a sample, comprising:

generating at least one source electro-magnetic radiation forwarded to the sample and a reference; and

detecting at least a portion of a signal associated with a combination of at least one first electro-magnetic radiation received from the sample and at least one second electro-magnetic radiation received from the reference using at least one detector of a plurality of detectors of a detection arrangement,

wherein at least one particular detector of the detectors has a particular electrical integration time, and wherein the at least one particular detector receives at least a portion of the signal for a time duration which has a first portion with a first power level greater than a predetermined threshold and a second portion immediately preceding or following the first portion, the second portion having a second power level less than the predetermined threshold, and extending for a time period which is approximately more than 10% of the particular electrical integration time.

32. The method according to claim 31, wherein the signal is at least one of frequency components of the combination.

33. The method according to claim 32, wherein the at least one particular detector receives the at least one of the frequency components.

34. The method according to claim 33, wherein the generating step is performed by a source arrangement which is a pulsed broadband source.

35. The method according to claim 34, wherein the at least one source electro-magnetic radiation generated by the pulsed source is a single pulse per the particular electrical integration time.

36. The method according to claim 35, wherein the pulsed source includes at least one of a Q-switched laser, a cavity-dumped mode-lock laser, and a gain-switched laser.

37. The method according to claim 34, wherein the at least one source electro-magnetic radiation generated by the source arrangement is a burst of radiation that extends for at most approximately 90% of the particular electrical integration time.

38. The method according to claim 37, wherein the burst of radiation includes multiple pulses.

39. The method according to claim 34, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a spectrum with a center wavelength between approximately 700 nanometers and 2000 nanometers.

40. The method according to claim 39, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a spectrum width a spectral width of approximately greater than 1% of the center wavelength.

41. The method according to claim 35, wherein the at least one source electro-magnetic radiation generated by the pulsed broadband source has a pulse width approximately shorter than 1 μ

sec.

42. The method according to claim 34, wherein a duration of the burst of radiation is approximately shorter than 1 μ

sec.

43. The method according to claim 33, wherein the source arrangement includes an optical gating switch.

44. The method according to claim 33, wherein a frequency of the at least one source electro-magnetic radiation varies over time.

45. The method according to claim 44, wherein a mean frequency of the at least one source electro-magnetic radiation changes substantially continuously over time at a tuning speed that is greater than 100 terahertz per millisecond.

46. The method according to claim 44, wherein the mean frequency changes repeatedly with a repetition period that is less than approximately 90% of the particular electrical integration time.

47. The method according to claim 44, wherein the at least one source electro-magnetic radiation generated by the source arrangement has a tuning range with a center wavelength between approximately 700 nanometers and 2000 nanometers.

48. The method according to claim 44, wherein the at least one source electro-magnetic radiation generated by the source arrangement has a tuning range of approximately greater than 1% of the center wavelength.

49. The method according to claim 44, wherein the at least one source electro-magnetic radiation generated by the source arrangement has an instantaneous line width and a tuning range, the instantaneous line width being less than approximately 10% of the tuning range.

50. The method according to claim 44, wherein the source arrangement includes a tunable laser.

51. The method according to claim 44, wherein the source arrangement includes a tunable filter.

52. The method according to claim 44, wherein the source arrangement includes a medium, and wherein the source arrangement generates the at least one source electro-magnetic radiation based on a non-linearity associated with the medium.

53. The method according to claim 44, wherein the frequency varies substantially linearly with time.

54. The method according to claim 44, wherein the frequency varies substantially sinusoidally with time.

55. The method according to claim 33, wherein the detector arrangement further includes an electrical shutter that is adapted to gate a transmission of photoelectrons associated with the combination of the first and second electro-magnetic radiation, wherein a time period for the gating to allow the transmission of the photoelectrons is less than approximately 90% of the particular electrical integration time.

56. The method according to claim 33, wherein the sample is a biological sample.

57. The method according to claim 33, wherein the detecting step is performed by a detection arrangement which includes at least one charged-coupled device.

58. The method according to claim 31, wherein the generating step is performed by a source arrangement which is a pulsed broadband source.

59. The method according to claim 31, wherein the detection step is performed by a detection arrangement which includes at least one charged-coupled device.

60. The method according to claim 33, further comprising the step of separating spectrum of at least one of the first electro-magnetic radiation, the second electro-magnetic radiation and the combination into the at least one of the frequency components.