# US 11,112,232 B2 · Apparatus and methods for mirror tunnel imaging device and for providing pseudobessel beams in a miniaturized optical system for imaging

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- Number: US 11,112,232 B2
- Document ID: US11112232B2
- Status: Granted
- Kind: B2
- Application number: 16/796,103
- Filed: 2020-02-20
- Published: 2020-07-09
- Granted: 2021-09-07
- Earliest claimed: 2015-09-16
- Assignees: The General Hospital Corporation
- Applicants: The General Hospital Corporation
- Inventors: Guillermo J. Tearney; Biwei Yin; Kengyeh K. Chu; Barry Vuong
- Web page: https://patentgrep.com/patent/US11112232B2

## CPC

- G01B 9/02035: {Shaping the focal point, e.g. elongated focus}
- A61B 5/0066: {Optical coherence imaging}
- A61B 5/0084: {for introduction into the body, e.g. by catheters (A61B5/1459 takes precedence)}
- G01B 9/02038: {Shaping the wavefront, e.g. generating a spherical wavefront}
- G01B 9/02091: Tomographic interferometers, e.g. based on optical coherence
- G02B 6/262: {Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements}
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

Exemplary apparatus and method are provided for illuminating a sample. With such exemplary apparatus and/or method, it is possible to, using at least one source arrangement, provide at least one first electro-magnetic radiation. Using an optical system of an optics arrangement, it is possible to receive the first electro-magnetic radiation(s), and modifying the at least one first electro-magnetic radiation to be at least one second electro-magnetic radiation so as to be forwarded to the sample. Further, with the optical system, it is possible to extend the at least one second electro-magnetic radiation into or across the sample for a distance of at least 2 times the Raleigh range of a Gaussian beam when the optics arrangement and the sample are stationary with respect to one another. Additionally, using the optical system, it is possible to control a placement of a focus of the at least one second electro-magnetic radiation on or in the sample.

## Claims

### Claim 1

An apparatus for illuminating a sample in an optical coherence tomography (OCT) system, comprising:
a first optical waveguide which emits light at a distal end thereof;
a second optical waveguide which receives the light from the distal end of the first optical waveguide and emits the light toward a lens,
the emitted light comprising a first beam and at least a second beam,
the first beam being transmitted toward the lens without being internally reflected within the second optical waveguide, and
the second beam being internally reflected within the second optical waveguide before being transmitted toward the lens; and
the lens being configured to direct the first beam and the second beam toward the sample,
the first beam forming a first beam waist at a first distance from the lens, and
the second beam forming a second beam waist at a second distance from the lens different from the first distance.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the first distance of the first beam waist from the lens substantially coincides with a focal plane of the lens.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the second optical waveguide converts the light into a plurality of propagation modes,
wherein the first beam corresponds to a 0th order propagation mode, and
wherein the second beam corresponds to a 1st order propagation mode.

### Claim 4 (depends on 3)

The apparatus of claim 3, wherein the number of propagation modes is based on a length of the second optical waveguide.

### Claim 5 (depends on 1)

The apparatus of claim 1, further comprising a spacer between the second optical waveguide and the lens.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein the lens comprises an optical axis, and
wherein the first beam is emitted through a surface of the lens at a first area and forms the first beam waist along the optical axis.

### Claim 7 (depends on 6)

The apparatus of claim 6, wherein the second beam is emitted through the surface of the lens at a second annular area including an outer radius that is greater than a radius of the first area, and
wherein the second beam forms the second beam waist along the optical axis.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the second optical waveguide comprises a mirror tunnel.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein the lens is disposed in a catheter.

### Claim 10 (depends on 1)

The apparatus of claim 1, wherein the lens is disposed in a swallowable capsule.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein the first optical waveguide is a single mode optical fiber, and wherein the second optical waveguide is a multimode optical fiber.

### Claim 12 (depends on 1)

The apparatus of claim 1, further comprising:
a light source optically coupled to a proximal end of the first optical waveguide; and
an image sensor optically coupled to the proximal end of the first optical waveguide.

### Claim 13

A method for illuminating a sample in an optical coherence tomography (OCT) system, comprising:
emitting light from a distal end of a first optical waveguide;
emitting, from a second optical waveguide, the light received from the distal end of the first optical waveguide toward a lens,
the emitted light comprising a first beam and at least a second beam,
the first beam being transmitted toward the lens without being internally reflected within the second optical waveguide, and
the second beam being internally reflected within the second optical waveguide before being transmitted toward the lens;
directing, by the lens, the first beam and the second beam toward the sample;
focusing, by the lens, the first beam into a first beam waist at a first distance from the lens; and
focusing, by the lens, the second beam into a second beam waist at a second distance from the lens different from the first distance.

### Claim 14 (depends on 13)

The method of claim 13, wherein the first distance of the first beam waist from the lens substantially coincides with a focal plane of the lens.

### Claim 15 (depends on 13)

The method of claim 13, wherein the second optical waveguide, when emitting the light received from the distal end of the first optical waveguide toward a lens, converts the light into a plurality of propagation modes,
wherein the first beam corresponds to a 0th order propagation mode, and
wherein the second beam corresponds to a 1st order propagation mode.

### Claim 16 (depends on 15)

The method of claim 15, wherein the number of propagation modes is based on a length of the second optical waveguide.

### Claim 17 (depends on 13)

The method of claim 13, wherein the second optical waveguide, when emitting the light received from the distal end of the first optical waveguide toward the lens, emits the light received from the distal end of the first optical waveguide toward the lens through a spacer disposed between the second optical waveguide and the lens.

### Claim 18 (depends on 13)

The method of claim 13, wherein the lens comprises an optical axis, and
wherein the lens, when directing the first beam and the second beam toward the sample, emits the first beam through a surface of the lens at a first area and form the first beam waist along the optical axis.

### Claim 19 (depends on 18)

The method of claim 18, wherein the lens, when directing the first beam and the second beam toward the sample, emits the second beam through the surface of the lens at a second annular area having an outer radius that is greater than a radius of the first area,
wherein the second beam forms the second beam waist along the optical axis.

### Claim 20 (depends on 13)

The method of claim 13, wherein the second optical waveguide comprises a mirror tunnel.

### Claim 21 (depends on 13)

The method of claim 13, wherein the lens is disposed in a catheter.

### Claim 22 (depends on 13)

The method of claim 13, wherein the lens is disposed in a swallowable capsule.

### Claim 23 (depends on 13)

The method of claim 13, wherein the first optical waveguide is a single mode optical fiber, and wherein the second optical waveguide is a multimode optical fiber.

### Claim 24 (depends on 13)

The method of claim 13, further comprising:
optically coupling a light source to a proximal end of the first optical waveguide; and
optically coupling an image sensor to the proximal end of the first optical waveguide.