Optical coherence tomography

Patent metadata

Field	Value
Publication number	US-9816802-B2
Application number	US-201113643036-A
Country	US
Kind code	B2
Filing date	Jun 2, 2011
Priority date	Jun 2, 2010
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An optical coherence tomography system comprising a light source (a) and a probe (e) that has a window at a front facing end. The window has an inner face (i) that has an anti-reflection surface and allows light from the source to pass through it, and an outer face (j) that reflects some of the light from the source and transmits some of the light to and from the sample (k). The reflected light acts as a reference.

First claim

The invention claimed is:

1. An optical coherence tomography system comprising a light source, a light detector and a front-facing probe, wherein the probe comprises a window at a front facing end, wherein the window has an inner face that has an anti-reflection surface and allows light from the source to pass through it, and an outer face which is to be positioned in close proximity to, or directly in contact with, a sample to be investigated, wherein the outer face is treated so that some of the light from the source incident upon a region of the outer face is backscattered to thereby form a scattered signal for use as a reference signal and so that some of the light from the source incident upon the same region of the outer face is transmitted to the sample, wherein at least a portion of the light incident upon the sample is backscattered from the sample as a transmitted signal, and wherein the transmitted signal interferes with the reference signal at the light detector.

2. A system as claimed in claim 1 wherein the anti-reflection surface is an anti-Newton surface.

3. A system as claimed in claim 1 wherein the outer face is roughened, thereby to cause backscattering of some of the light from the source to create the scattered signal for use as the reference signal.

4. A system as claimed in claim 1 wherein the scattered signal is small compared to the transmitted signal.

5. A system as claimed in claim 4 wherein the scattered light of the scattered signal is less than 50% of the transmitted light of the transmitted signal.

6. A system as claimed in claim 1 wherein the probe includes one or more optical elements.

7. A system as claimed in claim 6 wherein the optical element comprises at least one focusing means.

8. A system as claimed in claim 7 wherein the focusing means comprises at least one lens.

9. A system as claimed in claim 1 comprising an optical fiber for coupling light into and out of the probe.

10. A system as claimed in claim 9 wherein the end of the fiber is shaped to focus light in the probe.

11. A system as claimed in claim 9 wherein the fiber is treated to avoid or reduce reflections from the end that is coupled with the probe.

12. A system as claimed in claim 11 wherein the fiber end is coated with an anti-reflection material.

13. A system as claimed in claim 9 wherein an anti-reflection window is provided for coupling the fiber end to the probe.

14. A system as claimed in claim 13 wherein the anti-reflection window and fiber are coupled using a glue or an index matching material.

15. A front-facing probe comprising a window at a front facing end, wherein the window has an inner face that has an anti-reflection surface and allows light from a light source to pass through it, and an outer face which is to be positioned in close proximity to, or directly in contact with, a sample to be investigated, wherein the outer face is treated that some of the light from the source incident upon a region of the outer face is backscattered and to thereby form a scattered signal for use as a reference signal and so that some of the light from the source incident upon the same region of the outer face is transmitted to the sample, wherein at least a portion of the light incident upon the sample is backscattered from the sample as a transmitted signal, and wherein the transmitted signal and the reference signal follow a common path to permit interference of the transmitted signal with the reference signal.

16. A probe as claimed in claim 15 wherein the anti-reflection surface is an anti-Newton surface.

17. A probe as claimed in claim 15 wherein the outer face is roughened, thereby to cause backscattering of some of the light from the source to create the scattered signal for use as the reference signal.

18. A probe as claimed in claim 17 wherein the scattered signal is small compared to the transmitted signal.

19. A probe as claimed in claim 18 wherein the scattered light of the scattered signal is less than 50% of the transmitted light of the transmitted signal.

20. A probe as claimed in claim 15 including one or more optical elements.

21. A probe as claimed in claim 20 wherein the optical element comprises at least one focusing means.

22. A probe as claimed in claim 21 wherein the focusing means comprises at least one lens.

23. A probe as claimed in claim 15 wherein an anti-reflection window is provided for coupling a fiber end to the probe.

Assignees

• Dholakia Kishan
• Giardini Mario Ettore
• Univ Court Univ St Andrews

Inventors

• Dholakia Kishan
• Giardini Mario Ettore

Classifications

• G01N21/4795

  spatially resolved investigating of object in scattering medium (in vivo A61B) · CPC title

• G01N2021/4709

  Backscatter · CPC title

• G01B9/02091 Primary

  Tomographic interferometers, e.g. based on optical coherence · CPC title

• G01N21/474 Primary

  Details of optical heads therefor, e.g. using optical fibres · CPC title