Tissue scanning apparatus and method

1. A system for multispectral confocal mapping of a tissue, comprising:

a light source providing emissions;

an optical fiber having a first end optically coupled to receive the emissions and a second end having an aperture providing a confocal pinhole,

a scanner being free-space coupled to said aperture, said scanner operative to scan the tissue and provide intensity signals for each of a plurality of points therein, wherein said optical fiber receives the intensity signals at said aperture and propagates said intensity signals to said first end;

a switch or modulator optically coupled to said first end of said optical fiber and operative to convert said intensity signals to optical pulses;

a reflector optically coupled to receive the optical pulses and provide a temporal sequence of wavelength selective reflections of the optical pulses; and,

a detector optically coupled to receive the temporal sequence of wavelength selective reflections and provide an output suitable for populating a data cube indicative of the relative intensity of each point in the scanned tissue.

2. The system of claim 1 , wherein the optical fiber is a single mode fiber.

3. The system of claim 1 , wherein the optical fiber is a multi-mode fiber.

4. The system of claim 1 , wherein the optical fiber is a microstructured fiber.

5. The system of claim 1 , wherein the optical fiber is a polarization maintaining fiber.

6. The system of claim 1 , wherein said optical fiber has a diameter between about 1 and 3 microns for visible wavelengths.

7. The system of claim 1 , wherein said optical fiber has a diameter greater than about 3 microns for visible wavelengths.

8. The system of claim 1 , wherein the reflector comprises a series coupled array of fiber gratings.

9. The system of claim 8 , wherein the array of fiber gratings is unblazed.

10. The system of claim 8 , wherein said array comprises at least about 10 gratings.

11. The system of claim 8 , wherein said array comprises between about 20 and 50 gratings.

12. The system of claim 8 , wherein said array comprises between about 10 and 100 gratings.

13. The system of claim 1 , wherein the tissue comprises an ex-vivo tissue sample.

14. The system of claim 1 , wherein the tissue comprises an in-vivo tissue sample.

15. The system of claim 14 , wherein the scanner comprises an endoscope fiber bundle.

16. The system of claim 1 , wherein said scanner comprises an x-y MEMS scanner at least partially contained in an endoscope.

17. The system of claim 1 , wherein each optical pulse has a pulse width less than a delay between successive wavelength selective reflections in the temporal sequence of wavelength selective reflections.

18. The system of claim 1 , wherein the scanner is a resonant scanner.

19. The system of claim 1 , wherein said detector comprises a PIN detector.

20. The system of claim 1 , wherein said detector comprises a photomultiplier tube.

21. The system of claim 1 , wherein said detector comprises avalanche photodetector.

22. The system of claim 1 , wherein said wavelength selective reflections have wavelengths between about 400 and 1600 nanometers.

23. The system of claim 1 , wherein said reflector comprises a single chirped grating.

24. The system of claim 1 , wherein said scanner operates on millimeter (mm) scale fields.

25. The system of claim 1 , wherein the scanner operates on centimeter (cm) scale fields.

26. The system of claim 1 , wherein said light source comprises a laser.

27. The system of claim 1 , wherein said light source comprises one or more narrow band sources.

28. The system of claim 1 , wherein said light source comprises a broad band light source.

29. The system of claim 1 , wherein said optical fiber has a diameter between about 8-10 microns for the near infrared region.

30. A system for multispectral confocal mapping of a tissue, comprising:

a light source providing a series of broad spectrum emission pulses;

a plurality of reflectors optically coupled to receive the series of optical pulses and provide a temporal sequence of wavelength selective reflections of each of the optical pulses;

an optical fiber having a first end optically coupled to receive the temporal sequence of wavelength selective reflections and a second end having an aperture providing a confocal pinhole,

a scanner being free-space coupled to said aperture, said scanner operative to scan the tissue and provide intensity signals for each of a plurality of points therein, wherein said optical fiber receives the intensity signals at said aperture and propagates said intensity signals to said first end; and,

a detector optically coupled to receive the intensity signals and provide an output suitable for populating a data cube indicative of the relative intensity of each point in the scanned tissue.

31. A method for mapping a tissue, comprising:

scanning portions of the tissue, and for each portion:

coupling intensity signals from the then scanned portion of the tissue into an end of an optical fiber providing a confocal pinhole;

converting said intensity signals to optical pulses;

obtaining a temporal sequence of wavelength selective reflections of the optical pulses; and,

providing an output indicative of a relative intensity responsively to the temporal sequence of wavelength selective reflections.

32. A method for mapping tissue, comprising:

providing a temporal series of optical pulses;

providing a temporal sequence of wavelength selective reflections of each of the optical pulses;

impinging portions of the tissue with a corresponding one of the temporal sequence of wavelength selective reflections;

detecting light returned from each portion responsive to the impinging step; and

providing, in response to said detecting step, an output indicative of a relative intensity for each said portion of the tissue.