Methods and apparatus related to a side-fire member having a doped silica component

1. An apparatus, comprising:

an optical fiber including a surface non-normal to a longitudinal axis of a distal end portion of the optical fiber, wherein the surface defines a portion of an interface configured to redirect electromagnetic radiation propagated from within the optical fiber and incident on the interface in a direction offset from the longitudinal axis;

an intermediate cap fused to an outer-layer portion of the optical fiber such that the surface of the optical fiber is disposed within a cavity defined by the intermediate cap, wherein the intermediate cap is a fluorine-doped silica cap, and the fluorine doped silica cap includes a concentration of fluorine greater than a concentration of fluorine of the outer-layer portion of the optical fiber; and

an outer cap coupled to the intermediate cap, wherein the outer cap includes an opening aligned with the direction such that the electromagnetic radiation is transmitted through the opening.

2. The apparatus of claim 1 , wherein the intermediate cap has an index of refraction less than an index of refraction associated with a cladding layer of the optical fiber.

3. The apparatus of claim 1 , wherein the outer-layer portion of the optical fiber is a cladding layer of the optical fiber.

4. The apparatus of claim 1 , wherein the interface is a first interface and the outer-layer portion of the optical fiber is a cladding layer of the optical fiber, and wherein the intermediate cap and the cladding layer define a second interface such that electromagnetic radiation propagated within the cladding layer and incident on the second interface is substantially internally reflected within the cladding layer.

5. The apparatus of claim 1 , wherein the surface is disposed within a distal end portion of the intermediate cap, and wherein a proximal end portion of the intermediate cap is fused to the optical fiber.

6. The apparatus of claim 1 , wherein the surface is included in the distal end portion of the optical fiber, and wherein the intermediate cap is fused to a portion of the optical fiber proximal to the distal end portion of the optical fiber without being fused to the distal end portion of the optical fiber.

7. The apparatus of claim 1 , wherein the outer cap is a metallic cap, and the metallic cap comprises an inner surface configured to redirect electromagnetic radiation incident on the inner surface of the metallic cap into the cavity defined by the intermediate cap.

8. A method, comprising:

receiving an optical fiber, the optical fiber including a surface non-normal to a longitudinal axis of a distal end portion of the optical fiber;

moving an intermediate component over the surface of the optical fiber such that the surface of the optical fiber is disposed within a bore;

heating the intermediate component and the optical fiber such that at least a portion of an inner surface of the intermediate component defined by the bore may be fused to at least an outer-layer portion of the optical fiber, wherein the intermediate component is a fluorine-doped silica cap, and the fluorine doped silica cap includes a concentration of fluorine greater than a concentration of fluorine of the outer-layer portion of the optical fiber; and

moving an outer cap over the intermediate component, wherein the outer cap is substantially opaque to laser energy transmitted from the optical fiber.

9. The method of claim 8 , wherein the moving of the intermediate component includes moving until the surface of the optical fiber is disposed within the bore of the intermediate component.

10. The method of claim 8 , wherein the portion of the inner surface of the intermediate component defined by the bore is included in a proximal end of the intermediate component, and wherein, the bore of the intermediate component is a bore therethrough.

11. The method of claim 8 , wherein the portion of the inner surface of the intermediate component defined by the bore is included in a proximal end of the intermediate component, the bore of the intermediate component being a bore therethrough, the method further comprising:

heating a distal end of the intermediate component such that an enclosure is defined by the distal end of the intermediate component and the optical fiber.

12. The method of claim 8 , wherein the heating defines an interface, and wherein the intermediate component includes a doping concentration such that electromagnetic radiation from the optical fiber and incident on the interface is substantially internally reflected within the optical fiber.

13. The method of claim 8 , wherein the surface of the optical fiber defines a portion of an interface configured to redirect electromagnetic radiation propagated from within the optical fiber and incident on the interface to a lateral direction offset from the longitudinal axis; the method further comprising:

moving an outer cap over the intermediate component such that an opening defined by the outer cap is aligned with the lateral direction.

14. An apparatus, comprising:

a fluorine-doped silica cap; and

a distal end portion of an optical fiber that includes a surface disposed within the doped silica cap, wherein the fluorine-doped silica cap is coupled to an outer-layer portion of the optical fiber, and the fluorine-doped silica cap includes a concentration of fluorine greater than a concentration of fluorine of the outer-layer portion of the optical fiber;

wherein the surface defines at least a portion of an interface configured to redirect laser energy from a first portion of an optical path to a second portion of the optical path non-parallel to the first portion of the optical path, and wherein the second portion of the optical path intersects an outer surface of the fluorine-doped silica cap; and

an outer cap disposed over at least a portion of the fluorine-doped silica cap, wherein the outer cap is substantially opaque to laser energy.

15. The apparatus of claim 14 , wherein at least a portion of an inner surface of the fluorine-doped silica cap and at least a portion of the outer-layer portion of the distal end portion of the optical fiber define an interface, and wherein the doped silica cap includes a doping concentration such that electromagnetic radiation from the optical fiber and incident on the interface is substantially internally reflected within the optical fiber.

16. The apparatus of claim 14 , wherein the outer cap is a metallic cap, and, wherein the second portion of the optical path may intersect an opening of the metallic cap.