Improvements in and relating to optical fibres
(19)AUSTRALIAN PATENT OFFICE(54) Title Improvements in and relating to opticalfibres(51)6 International Patent Classification(s) G02B 006/245 G02B 006/22 G02B 006/16 G02B 006/25 (21) Application No: 2003201638 (22) Application Date: 2003 .01 .07 (87) WIPO No: WO03/058310 (30) Priority Data (31) Number (32) Date 0200615.3 2002.01.11 (33) Country GB 200510207 (43) (43) Publication Date : 2003 .07.24 Publication Journal Date : 2003 .09.04 (71) Applicant(s) BLAZEPHOTONICS LIMITED(72) Inventor(s) Kakarantzas, George; Russell, PhilipAdam; Wadsworth, William JohnSt.John; Knight, Jonathan Cave; Birks, Timothy(-1-1) Application NoAU2003201638 A8(19)AUSTRALIAN PATENT OFFICE(54) Title Improvements in and relating to opticalfibres(51)6 International Patent Classification(s) G02B 006/245 G02B 006/22 G02B 006/16 G02B 006/25 (21) Application No: 2003201638 (22) Application Date: 2003 .01 .07 (87) WIPO No: WO03/058310 (30) Priority Data (31) Number (32) Date 0200615.3 2002.01.11 (33) Country GB 200510207 (43) (43) Publication Date : 2003 .07.24 Publication Journal Date : 2003 .09.04 (71) Applicant(s) BLAZEPHOTONICS LIMITED(72) Inventor(s) Kakarantzas, George; Russell, PhilipAdam; Wadsworth, William JohnSt.John; Knight, Jonathan Cave; Birks, Timothy-1- An optical fibre and a method of processing the optical fibre are disclosed. The fibre comprises an inner rod (100) and an outer tube (140). The inner rod (100) is supported in the outer tube (140) by a plurality of webs (160). The webs (160) are sufficiently thin for the outer tube (140) to be cleavable without cleaving of the inner rod (100). The method comprises cleaving the outer tube (140) in a cleaving action that does not cleave the inner rod (100). Claims 1. A method of processing an optical fibre, the fibre comprising an inner rod and an outer tube, the inner rod being supported in the outer tube by a plurality of webs, the webs being sufficiently thin for the outer tube to be cleavable without cleaving of the inner rod, the method comprising cleaving the outer tube in a cleaving action that does not cleave the inner rod.
2. A method as claimed in claim 1, further comprising removing a portion of the outer tube to expose a portion of the inner rod.
3. A method as claimed in claim 2, further comprising the step of polishing the exposed portion of the inner rod.
4. A method as claimed in claim 2 or claim 3, further comprising the step of tapering the exposed portion of the inner rod.
5. A method as claimed in any of claims 2 to 4, in which the portion of the outer tube is removed from part way along the fibre.
6. A method as claimed in any of claims 2 to 4, in which the portion of the outer tube is removed from an end of the fibre 7. A method as claimed in any preceding claim, further comprising cleaving the inner rod in another cleaving action.
8. A method as claimed in claim 7, in which the inner rod is cleaved in a different position along the fibre from the position in which the outer tube is cleaved, such that a portion of the inner rod projects beyond a cleaved facet of the outer tube.
9. A method as claimed claim 8, further comprising the step of splicing the projecting portion of the inner rod to another fibre. <Desc/Clms Page number 19> 10. A method as claimed claim 9, in which the other fibre is an inner rod of a fibre comprising the inner rod and an outer tube, the inner rod being supported in the outer tube by a plurality of webs.
11. A method as claimed in claim 10, in which the splice is to a portion of the inner rod of the other fibre that projects beyond a cleaved facet of the outer tube of the other fibre.
12. A method as claimed in any of claims 9 to 11, in which the splice is further processed after it is formed.
13. A method as claimed in any preceding claim, in which the inner rod is heated to alter its optical properties and/or its physical properties.
14. A method as claimed in any preceding claim, further comprising the step of passing a fluid between the inner rod and the outer tube.
15. A method as claimed in claim 14, in which the fluid is used to cool the inner rod or the outer tube.
16. A method as claimed in claim 14, in which the fibre is used to sense a property of the fluid.
17. A method as claimed in any preceding claim, in which the fibre comprises a plurality of inner rods supported in the outer tube by a plurality of webs.
18. A method as claimed in claim 17, comprising cleaving the plurality of inner rods separately from the outer tube.
19. A method as claimed in claim 18, in which the plurality of inner rods are cleaved independently from each other.
20. An optical fibre comprising an inner rod and an outer tube, the inner rod being supported in the outer tube by a plurality of webs, the webs being sufficiently thin for the outer tube to be cleavable without cleaving of the inner rod.
21. An optical fibre as claimed in claim 20, in which the inner rod has an exposed portion not covered by the outer tube. <Desc/Clms Page number 20> 22. A fibre as claimed in claim 21, in which the inner rod is tapered in the exposed portion.
23. A fibre as claimed in claim 21 or claim 22, in which the exposed portion is part way along the fibre.
24. A fibre as claimed in claim 21 or claim 22, in which the exposed portion is at an end of the fibre, such that the exposed portion forms a portion of the inner rod projecting from the outer tube.
25. A fibre as claimed in claim 24, in which the inner rod has a cleaved facet in the exposed portion such that the exposed portion forms a portion of the inner rod projecting from the outer tube.
26. A fibre as claimed in claim 25, further comprising another fibre to which the projecting portion of the inner rod is connected by a splice at the cleaved facet.
27. A fibre as claimed in claim 26, in which the other fibre is an inner rod of a fibre comprising the inner rod and an outer tube, the inner rod being supported in the outer tube by a plurality of webs.
28. A fibre as claimed in claim 27, in which the splice is to a projecting portion of the inner rod of the other fibre.
29. A fibre as claimed in any of claims 20 to 28, in which the inner rod comprises a core region and a cladding region for confining light to the core region.
30. A fibre as claimed in claim 29, in which the cladding region comprises a plurality of elongate regions having a different refractive index from a matrix region in which they are embedded.
31. A fibre as claimed in any of claims 20 to 30, in which the inner rod is a tube.
32. A fibre as claimed in any of claims 20 to 28, in which the inner rod has no internal structure.
33. A fibre as claimed in any of claims 20 to 28, in which the inner rod comprises a plurality of elongate regions which form a photonic crystal not having a core region. <Desc/Clms Page number 21> 34. A fibre as claimed in any of claims 20 to 33, in which a region of the inner rod has been doped with an active ion.
35. A fibre as claimed in claim 34, which is, or is part of, a fibre laser.
36. A fibre as claimed in claim 34 or 35 when dependent on claim 21, in which pump light is introduced into the inner rod by side pumping the exposed portion.
37. A fibre as claimed in any preceding claim, in which the outer tube partially surrounds the inner rod in a transverse cross-section of the fibre.
38. A fibre coupler comprising a first fibre and a second fibre, the first fibre being a fibre as claimed in claim 21 and being fused, at the exposed portion of the inner rod, to the second fibre.
39. A fluid monitor comprising a fibre as claimed in any of claims 20 to 37.