Optical fiber apparatus with high divergence angle and light source system using same

Patent metadata

Field	Value
Publication number	US-2019025492-A1
Application number	US-201716069715-A
Country	US
Kind code	A1
Filing date	Jan 27, 2017
Priority date	Jan 29, 2016
Publication date	Jan 24, 2019
Grant date	—

Abstract

A high-divergence-angle optical fiber apparatus is disclosed that includes a multimode optical fiber having a distal end and a divergence angle θ′. A light-redirecting structure is operably disposed at the distal end and consists of an array of between 1 and 10 layers of fused glass microspheres. The light-redirecting structure defines a divergence angle θ, wherein θ≥2θ′. A light source system that utilizes the high-divergence-angle optical fiber apparatus is also disclosed.

First claim

What is claimed is:

1 . An high-divergence-angle (HDA) optical fiber apparatus, consisting of:
a multimode optical fiber having a glass core, a lower-index glass cladding surrounding the glass core, a proximal end and a distal end, wherein the optical fiber has a divergence angle θ′; a light-redirecting structure operably disposed at the distal end and consisting of an array of fused glass microspheres having diameters in the range from 3 microns to 25 microns wherein the array is fused to the distal end and has between 1 layer and 10 layers of microspheres; and wherein the light-redirecting structure defines a divergence angle θ, wherein θ≥2θ′.

2 . The HDA optical fiber apparatus according to claim 1 , wherein the optical fiber has a core diameter D 1 of nominally 40 microns and a cladding outer diameter D 2 of nominally 50 microns.

3 . The HDA optical fiber apparatus according to claim 1 , wherein the glass microspheres, the glass core and the glass cladding are each made of a silica-based glass.

4 . The HDA optical fiber apparatus according to claim 1 , wherein the array has between 1 layer and 6 layers of the microspheres.

5 . The HDA optical fiber apparatus according to claim 1 , wherein the microspheres are solid.

6 . The HDA optical fiber apparatus according to claim 1 , wherein θ≥3θ′.

7 . The HDA optical fiber apparatus according to claim 1 , wherein the core has a diameter D 1 and includes adjacent the distal end a widened core section that has a diameter D 1 ′ that is at least 5% greater than the core diameter D 1 .

8 . The HDA optical fiber apparatus according to claim 1 , wherein the distal end of the optical fiber is curved.

9 . The HDA optical fiber apparatus according to claim 1 , wherein the distal end of the optical fiber includes depressions and protrusions that have a size substantially the same as the glass microspheres.

10 . The HAD optical fiber apparatus according to claim 1 , wherein the fused microspheres define air-filled interstices within the light-redirecting structure.

11 . A light source system, comprising:
the HDA optical fiber apparatus according to claim 1 ; and a light source optically coupled to the proximal end of the optical fiber and that includes a light emitter that emits light that is coupled into the optical fiber, wherein the light is emitted from the light-redirecting structure as divergent light over the second divergence angle θ.

12 . The light source system according to claim 11 , wherein the light emitter emits non-polarized visible light in the range from 440 nm to 650 nm.

13 . A method of forming a high-divergence-angle (HDA) optical fiber apparatus using a multimode optical fiber having a glass core, a lower-index glass cladding surrounding the glass core, a proximal end and a distal end, wherein the optical fiber has a first divergence angle θ′, the method comprising:
arranging an array of glass microspheres adjacent the distal end,

the microspheres having diameters in the range from 3 microns to 25 microns; and
applying heat to the microspheres and to the distal end to fuse the microspheres to each other and to the distal end to form a light-redirecting structure that consists only of the microspheres and that defines a second divergence angle θ, wherein θ≥2θ′.

14 . The method according to claim 13 , further comprising:
prior to the act of applying heat, using a binding material to bind the microspheres to each other and to the distal end of the optical fiber; and wherein the act of applying heat includes burning off substantially all of the binding material.

15 . The method according to claim 13 , wherein the optical fiber has a core diameter of nominally 40 microns and a cladding outer diameter of nominally 50 microns.

16 . The method according to claim 13 , wherein the glass microspheres, the core and the cladding are made of a silica-based glass.

17 . The method according to claim 13 , wherein the array has between 1 layer and 6 layers of microspheres.

18 . The method according to claim 13 , wherein the microspheres are solid.

19 . The method according to claim 13 , wherein the fused microspheres define air-filled interstices within the light-redirecting structure.

20 . The method according to claim 13 , wherein the core has a diameter D 1 and further including a widened core section adjacent the distal end, the widened core section having a diameter D 1 ′ that is at least 5% greater than the core diameter D 1 .

21 . The method according to claim 13 , further comprising forming the distal end of the optical fiber to have a convex curvature.

22 . The method according to claim 13 , further comprising forming protrusions and depressions on the distal end of the optical fiber, wherein the protrusion and depressions have a size substantially the same as the microspheres.

23 . The method according to claim 13 , further comprising:
operably arranging a light source relative to the proximal end of the optical fiber and emitting a divergent light beam from the light-redirecting structure.

24 . The method according to claim 23 , wherein the light source emits non-polarized broadband visible light over a spectral range from 440 nm to 650 nm.

25 . The method according to claim 23 , further including immersing the light-redirecting structure in a biological fluid.

26 . A light source system that emits divergent light of a visible wavelength λ, comprising:
a multimode optical fiber having a proximal end and a distal end, and a divergence angle θ′;
a light-redirecting structure operably disposed at the distal end and consisting of an array of fused glass microspheres having diameters in the range from 3 microns to 25 microns, wherein the light-redirecting structure is fused to the distal end and has between 1 layer and 10 layers of microspheres and defines a divergence angle θ, wherein θ≥2θ′; and
a light source optically coupled to the proximate end of the optical fiber and that emits light of the visible wavelength λ.

Assignees

• Corning Inc

Inventors

• Bhagavatula Venkata Adiseshaiah

Classifications

• A61B1/313

  for introducing through surgical openings, e.g. laparoscopes · CPC title

• A61B1/07

  using light-conductive means, e.g. optical fibres · CPC title

• G02B6/0008 Primary

  the light being emitted at the end of the fibre · CPC title

• G02B6/02295

  Microstructured optical fibre (polarisation properties thereof G02B6/105 and G02B6/024) · CPC title

• A61B3/0008

  provided with illuminating means (A61B3/117, A61B3/14 take precedence) · CPC title