Claims
- 1. A fiber collimator comprising an optical element and at least one optical fiber fusion-spliced to a surface thereof, said surface of said optical element provided with a gradient in index of refraction at least where said at least one optical fiber is fusion-spliced thereto.
- 2. The fiber collimator of claim 1 wherein said gradient in said surface of said optical element has a thickness of at least 0.2 μm.
- 3. The fiber collimator of claim 2 wherein said thickness is less than about 2 μm.
- 4. The fiber collimator of claim 1 wherein said optical element is a collimating lens having a surface to which said at least one optical fiber is attached that is normal to said at least one optical fiber.
- 5. The fiber collimator of claim 4 wherein said collimating lens and said at least one optical fiber are secured in a mounting sleeve.
- 6. The fiber collimator of claim 1 wherein said optical element is a plano-plano pellet having a surface to which said at least one optical fiber is attached that is normal to said at least one optical fiber.
- 7. The fiber collimator of claim 6 wherein said plano-plano pellet and said at least one optical fiber are secured in a mounting sleeve, said mounting sleeve in turn secured in a housing provided with a chamber, said mounting sleeve located at one end of said chamber and a collimating lens located at an opposite end of said chamber.
- 8. A method for fusion-splicing at least one optical fiber to an optical element with a laser beam, said optical element having a surface that has a comparatively larger cross-sectional area than a surface of said at least one optical fiber, said method comprising:
(a) aligning said at least one optical fiber along a common axis axis, perpendicular to said surface of said optical element; (b) turning on a directional laser heat source to form said laser beam; (c) directing said laser beam to be collinear with said at least one optical fiber; (d) ensuring that said laser beam strikes said surface of said optical element at normal or near normal incidence so that absorption of said laser beam is much more efficient on said surface; (e) adjusting the power level of said laser beam to reach a temperature equal to or higher than the softening temperature of said surface of said optical element to form a softening region thereon, thereby achieving said fusion-splicing; (f) forming a gradient in index of refraction in said surface of said optical element, either prior to or during said fusion-splicing; and (g) turning off said laser heat source.
- 9. The method of claim 8 wherein said larger cross-sectional area is at least two times larger than that of said at least one optical fiber.
- 10. The method of claim 9 wherein said larger cross-sectional area is at least ten times larger than that of said at least one optical fiber.
- 11. The method of claim 8 wherein said at least one optical fiber and said optical element comprise silica-based glasses.
- 12. The method of claim 11 wherein said laser operates in a wavelength region of about 9 to 11 μm.
- 13. The method of claim 12 wherein said laser is a CO2 laser.
- 14. The method of claim 8 wherein said directing of said laser beam to be collinear with said at least one optical fiber is achieved by providing a mirror having a hole therethrough, through which said at least one optical fiber passes.
- 15. The method of claim 14 wherein said mirror is inclined at 45-degrees with respect to said optical fibers.
- 16. The method of claim 8 wherein said at least one optical fiber is aligned but separated by a space from said optical element, said laser beam is turned on to form said softening region on said surface of said optical element, and said surface of said at least one optical fiber is brought in contact with said softening region of said optical element, said contact resulting in heat transfer to said surface of said at least one optical fiber, which then softens, thereby achieving said fusion-splicing.
- 17. The method of claim 8 wherein said at least one optical fiber is first brought into contact with said surface of said optical element and said laser beam is then turned on to form said softening region where said at least one optical fiber is in contact with said surface of said optical element to achieve said fusion-splicing.
- 18. The method of claim 8 wherein said at least one optical fiber is aligned, then brought into contact with said surface of said optical element, then separated by a space, said laser beam is turned on to form said softening region on said surface of said optical element, and said surface of said at least one optical fiber is brought in contact with said softening region of said optical element, said contact resulting in heat transfer to said surface of said at least one optical fiber, which then softens, thereby achieving said fusion-splicing.
- 19. The method of claim 8 wherein both said optical element and said at least one optical fiber have similar thermal and mechanical properties.
- 20. The method of claim 8 wherein said optical element is selected from the group consisting of lenses, filters, gratings, prisms, and wavelength division multiplexer devices.
- 21. The method of claim 20 wherein said optical element is a collimating lens.
- 22. The method of claim 8 wherein said gradient in said surface of said optical element is formed during said fusion-splicing.
- 23. The method of claim 8 wherein said gradient in said surface of said optical element is formed prior to said fusion-splicing.
- 24. The method of claim 23 wherein said optical fiber comprises a core surrounded by a cladding, said core being doped with at least one dopant and wherein said surface of said optical element is first coated with said at least one dopant and said at least one dopant is diffused into said surface.
- 25. The method of claim 8 wherein said gradient is formed to a thickness of at least 0.2 μm.
- 26. The method of claim 25 wherein said thickness is less than about 2 μm.
- 27. A method of increasing power handling capacity and improving pointing accuracy in a fiber collimator comprising an optical element and at least one optical fiber secured to a portion of a surface thereof, said method comprising:
(a) forming a gradient in index of refraction in at least said portion of said surface of said optical element; and (b) fusion-splicing said at least one optical fiber to said portion of said surface of said optical element.
- 28. The method of claim 27 wherein said optical element is selected from the group consisting of lenses, filters, gratings, prisms, and wavelength division multiplexer devices.
- 29. The method of claim 28 wherein said optical element is a collimating lens.
- 30. The method of claim 27 wherein said gradient in said surface of said optical element is formed during said fusion-splicing.
- 31. The method of claim 27 wherein said gradient in said surface of said optical element is formed prior to said fusion-splicing.
- 32. The method of claim 31 wherein said optical fiber comprises a core surrounded by a cladding, said core being doped with at least one dopant and wherein said surface of said optical element is first coated with said at least one dopant and said at least one dopant is diffused into said surface.
- 33. The method of claim 27 wherein said gradient is formed to a thickness of at least 0.2 μm.
- 34. The method of claim 33 wherein said thickness is less than about 2 μm.
- 35. The method of claim 27 wherein said optical element is a collimating lens having a surface to which said at least one optical fiber is attached that is normal to said at least one optical fiber.
- 36. The method of claim 35 wherein said collimating lens and said at least one optical fiber are secured in a mounting sleeve.
- 37. The method of claim 35 wherein said optical element is a plano-plano pellet having a surface to which said at least one optical fiber is attached that is normal to said at least one optical fiber.
- 38. The method of claim 37 wherein said plano-plano pellet and said at least one optical fiber are secured in a mounting sleeve, said mounting sleeve in turn secured in a housing provided with a chamber, said mounting sleeve located at one end of said chamber and a collimating lens located at an opposite end of said chamber.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation-in-part of application Ser. No. 09/118,033, filed Jul. 17, 1998, and is related (1) to co-pending application Ser. No. ______, filed ______ [D-98032A], which is also a continuation-in-part application of the '033 application, and (2) to co-pending application Ser. No. ______, filed ______ [D-98032C], which is a divisional application of the '033 application.
Divisions (1)
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Number |
Date |
Country |
Parent |
09450473 |
Nov 1999 |
US |
Child |
10013642 |
Nov 2001 |
US |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
09118033 |
Jul 1998 |
US |
Child |
09450473 |
Nov 1999 |
US |