Surface structure modification
A method of forming an optical fiber tip, the method including, roughening at least part of an end portion of the optical fiber; and, etching the roughed end portion to thereby form an optical fiber tip.
1. A method of forming an optical fiber tip, the method including:
a) shaping an end portion of the optical fiber by etching the end portion;
roughening at least part of the shaped end portion of an optical fiber by abrading the shaped end portion using a particle beam, and
c) etching the roughened end portion to thereby form an optical fiber tip.
2. A method according to claim 1 , wherein a surface of the optical fiber tip has multiple facets.
3. A method according to claim 2 , wherein the facets are rounded with a concave form.
4. A method according to claim 2 , wherein each facet is for distributing incident radiation at multiple angles.
5. A method according to claim 2 , wherein the facets have a size in the region of 10 μm to 100 μm.
6. A method according to claim 1 , wherein the optical fiber tip has a honeycomb surface structure.
7. A method according to claim 1 , wherein the method includes:
a) rotating the shaped end portion; and,
b) exposing the rotating shaped end portion to the particle beam.
8. A method according to claim 1 , wherein the particle beam includes particles of at least one of:
a) aluminium oxide;
b) cubic boron nitride;
c) silicon carbide;
d) silicon dioxide;
e) zirconium oxide;
f) zirconium dioxide;
g) silicone carbide;
h) corundum; and
i) magnesium oxide.
9. A method according to claim 1 , wherein the particles have an average size of at least one of:
a) between 25 and 100 m; and
b) approximately 50 m.
10. A method according to claim 1 , wherein the particle beam is generated using a compressed gas.
11. A method according to claim 10 , wherein the gas is at least one of:
a) air;
b) nitrogen;
c) carbon dioxide; and,
d) a non-flammable gas.
12. A method according to claim 10 , wherein the gas has a pressure of approximately 2.8 bar.
13. A method according to claim 1 , wherein the method includes etching the roughened end portion using an acid.
14. A method according claim 13 , wherein the acid includes at least one of:
a) hydrofluoric acid;
b) a mixture of hydrofluoric acid and orthophosphoric acid; and,
c) a mixture of hydrofluoric acid, orthophosphoric acid and a fluoride compound.
15. A method according to claim 13 , wherein the acid is in at least one of:
a) a vapour phase; and,
b) a liquid phase.
16. A method according to claim 13 , wherein the method includes etching the roughened end portion for between 10 and 15 minutes.
17. A method according to claim 1 , wherein the method includes shaping the end portion so that the shaped end portion tapers towards an end of the optical fiber.
18. A method according to claim 1 , wherein the method includes shaping the end portion into a conical shape.
19. A method according to claim 1 , wherein the method includes shaping the end portion by etching the end portion using an acid.
20. A method according to claim 19 , wherein the method includes shaping the end portion by etching the end portion for between 45 and 180 minutes.
21. A method according to claim 1 , wherein the method includes removing a polymer coating from the optical fiber to expose the end portion.
22. A method according to claim 1 , wherein the optical fiber is at least one of:
a) a silica glass fiber;
b) a fluoride doped silica glass fiber; and,
c) a germanium doped silica glass fiber.