Optical coherence tomography system and method with multiple apertures

• US 9,993,153 B2
• Filed: 07/06/2016
• Issued: 06/12/2018
• Est. Priority Date: 07/06/2016
• Status: Active Grant

• Current Assignee: Santec Holdings Corp.
• Original Assignee: Santec Incorporated
• Inventors: Chong, Changho
• Primary Examiner(s): TRA, TUYEN Q
• Application Number:
  US15/202,925
• Publication Number:
  US 20180008143A1
• Time in Patent Office: 706 Days
• Field of Search: 351206, 351205, 351200, 351208
• CPC Class Codes: A61B 3/0025 characterised by electronic signal processing, e.g. eye models
• CPC Class Codes: A61B 3/0041 characterised by display arrangements
• CPC Class Codes: A61B 3/0091 Fixation targets for viewing direction
• CPC Class Codes: A61B 3/102 for optical coherence tomography [OCT]
• CPC Class Codes: A61B 3/152 for aligning
• CPC Class Codes: G01B 9/02028 Two or more reference or object arms in one interferometer
• CPC Class Codes: G01B 9/0203 With imaging systems
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G02B 26/0816 by means of one or more reflecting elements
• CPC Class Codes: G02B 26/0883 the refracting element being a prism
• CPC Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 27/283 used for beam splitting or combining
• CPC Class Codes: G02B 27/285 comprising arrays of elements, e.g. microprisms

Abstract

An optical coherence tomography (OCT) system using partial mirrors is generally described. In an example, the OCT system includes a swept light source. The system further includes an interferometer into which light from the light source is directed and a detector configured to produce an imaging sample signal based on light received from the interferometer. The system also includes a partial mirror disposed over an aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range.

Claims

1. An optical coherence tomography (OCT) system comprising:

a light source configured to emit a light beam;

an interferometer configured to split the light beam into a reference beam and a sample beam;

a mirror system configured to route the sample beam to at least one of a first aperture or a second aperture for imaging of a sample, wherein the mirror system further comprises a switching mirror configured to selectively direct at least a portion of the sample beam into the first aperture or direct at least a portion of the sample beam towards the second aperture;

a first partial mirror positioned across at least a portion of the first aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range; and

a detector configured to detect a signal based on an interference between the reference beam and a portion of the sample beam reflected from the sample.

2. The system of claim 1, further comprising a second partial mirror positioned across at least a portion of the second aperture, wherein the second partial mirror is configured to transmit light within the first wavelength range and reflect light within the second wavelength range.

3. The system of claim 1, wherein the first partial mirror is positioned across at least a portion of each of the first and second apertures.

4. The system of claim 1, wherein the switching mirror comprises a polarized beam splitter configured to direct light having a first polarization direction toward the first aperture and to direct light having a second polarization direction toward the second aperture.

5. The system of claim 4, wherein the second polarization direction is perpendicular to the first polarization direction.

6. The system of claim 1, further comprising an actuator configured to selectively move the switching mirror into and out of a sample path to selectively direct the sample beam toward the first aperture or the second aperture.

7. The system of claim 1, further comprising a fixation mark etched on the partial mirror, wherein the fixation mark is aligned with an optical axis along which the sample beam is configured to pass through the first aperture.

8. The system of claim 1, further comprising a fixation light positioned behind the partial mirror, wherein the fixation light is configured to emit a beam of light along an optical axis along which the sample beam is configured to pass through the first aperture.

9. The system of claim 1, further comprising an eye cup disposed over the first aperture.

10. The system of claim 1, wherein the first partial mirror comprises an anti-reflection coating.

11. The system of claim 1, further comprising a display integrated into the first partial mirror, wherein the display is configured to present measured diagnostic information based on the detected signal.

12. An optical coherence tomography (OCT) system comprising:

a light source configured to emit a light beam;

an interferometer configured to split the light beam into a reference beam and a sample beam;

a mirror system configured to route the sample beam to a first aperture for imaging of a sample;

a first partial mirror positioned across at least a portion of the first aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range;

a detector configured to detect a signal based on an interference between the reference beam and a portion of the sample beam reflected from the sample;

a distance sensor configured to sense a distance of the sample from the first aperture; and

an alarm configured to indicate when the distance is within a range suitable for conducting a measurement with the OCT system.

13. A method of using an optical coherence tomography (OCT) system comprising:

emitting a beam from a light source;

splitting the beam into a reference beam and a sample beam at an interferometer;

directing, via a mirror system, the sample beam through a first aperture and through a partial mirror disposed over at least a portion of the first aperture, wherein the partial mirror is configured to transmit light within a first wavelength range and reflect light within a second wavelength range, and wherein the mirror system comprises a switching mirror configured to selectively direct the sample beam toward the first aperture or toward a second aperture;

directing, via the mirror system, a portion of the sample beam reflected from a sample to a detector;

comparing, via the detector, the reference beam with the portion of the sample beam reflected from the sample to generate a measurement signal corresponding to the sample.

14. The method of claim 13, wherein the switching mirror comprises a polarized beam splitter, the method further comprising directing, by the polarized beam splitter, the sample beam toward either the first aperture or the second aperture based on a polarization direction of the sample beam, wherein light having a first polarization direction is directed toward the first aperture and light having a second polarization is directed toward the second aperture, and wherein the first polarization direction is perpendicular to the second polarization direction.

15. The method of claim 13, further comprising moving, via an actuator, the switching mirror into and out of a path of the sample beam, wherein the switching mirror is configured to direct light to the second aperture when the switching mirror is located within the path of the sample beam, and wherein the sample beam passes to the first aperture when the switching mirror is not located within the path of the sample beam.

16. A method of using an optical coherence tomography (OCT) system comprising:

aligning an eye of a patient with a first aperture using a reflection in a partial mirror disposed over at least a portion of the first aperture, wherein the partial mirror is configured to pass infrared light and reflect visible light;

aligning the eye with a fixation mark disposed on the partial mirror, wherein the fixation mark is disposed along an optical axis of the sample beam; and

receiving a sample beam at the eye, wherein the sample beam passes through the first aperture and the partial mirror and is reflected back into the OCT system, and wherein a measurement of the eye is based on the reflected sample beam.

17. The method of claim 16, wherein aligning the eye with the first aperture further comprises aligning the eye with a fixation light emitted through the first aperture, wherein the fixation light is disposed along an optical axis of the sample beam.