System for diffusing light from an optical fiber or light guide

• US 20080019657A1
• Filed: 07/18/2006
• Published: 01/24/2008
• Est. Priority Date: 06/30/2005
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Wilson, Thomas, Small, Ward, Maitland, Duncan, Benett, William
• Granted Patent: US 7,386,203 B2
• Time in Patent Office: Days
• US Class Current: 385/140
• CPC Class Codes: G02B 6/0008 the light being emitted at the end of the fibre
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

A system for diffusing light from an optical fiber wherein the optical fiber is coupled to a light source, comprising forming a polymer element adapted to be connected to the optical fiber and incorporating a scattering element with the polymer element wherein the scattering element diffuses the light from the polymer element. The apparatus of the present invention comprises a polymer element operatively connected to the optical fiber and a scattering element operatively connected with the shape polymer element that diffuses the light from the polymer element.

Claims

1. An apparatus that guides light from a light source to a target area away from the light source, comprising:

an optical fiber, said optical fiber having a light transmitting core, a cladding layer about the core, a proximal end, and a distal end, the proximal end of the optical fiber being coupled to a the light source,

a light transmitting polymer element that is operatively connected to the distal end of the optical fiber, said light transmitting polymer element comprised of a shape memory polymer, and

wherein said light transmitting polymer element is comprised of a light diffusing element incorporated with said light transmitting polymer element to diffuse light radially outward from said light transmitting polymer element.

2. The light diffusing apparatus of claim 1 wherein said polymer element comprises a solid polymer body.

3. The light diffusing apparatus of claim 1 wherein said polymer element comprises a porous foam polymer body and wherein said scattering element comprises the inherent porous structure of said porous foam polymer body.

4. The light diffusing apparatus of claim 1 wherein said polymer element comprises a solid polymer body and a porous foam polymer body about the solid polymer body.

5. The light diffusing apparatus of claim 1 wherein said polymer element comprises a polymer coating over the exposed core at the distal end of the optical fiber, said cladding layer being removed to expose said core, said polymer coating having a refractive index equal to or slightly greater than that of the exposed core.

6. The light diffusing apparatus of claim 1 wherein said polymer element comprises a solid shape memory polymer.

7. The light diffusing apparatus of claim 1 wherein said polymer element comprises a porous foam shape memory polymer and wherein said scattering element comprises the inherent porous structure of said porous foam shape memory polymer body.

8. The light diffusing apparatus of claim 1 wherein said polymer element comprises a solid shape memory polymer body and a porous foam shape memory polymer body about the solid shape memory polymer body.

9. The light diffusing apparatus of claim 1 wherein said polymer element comprises a cylindrical polymer body.

10. The light diffusing apparatus of claim 1 wherein said polymer element comprises a spherical polymer body.

11. The light diffusing apparatus of claim 1 wherein said polymer element comprises two or more polymer sections cascaded together, said polymer sections having different glass transition temperatures to provide variable axial stiffness along the length of said polymer element.

12. The light diffusing apparatus of claim 1 including a socket-epoxy joint connecting said polymer element to the optical fiber.

13. The light diffusing apparatus of claim 1 wherein said polymer element is molded around the optical fiber.

14. The light diffusing apparatus of claim 1 wherein said scattering element causes uniform 360°

light emission radially outward over the surface of said polymer element.

15. The light diffusing apparatus of claim 1 wherein said scattering element causes a non-uniform pattern of light emission radially outward over the surface of said polymer element.

16. The light diffusing apparatus of claim 1 wherein said scattering element causes light to be emitted from one or more distinct areas over the surface of said polymer element.

17. The light diffusing apparatus of claim 1 wherein said scattering element causes light to be emitted in a single side-firing mode.

18. The light diffusing apparatus of claim 1 wherein said scattering element causes light to be emitted in a dual side-firing mode.

19. The light diffusing apparatus of claim 1 wherein said scattering element comprises a roughened surface of said polymer element.

20. The light diffusing apparatus of claim 1 wherein said scattering element comprises a roughened surface of said polymer element, said roughened surface having scattering sites, the density of scattering sites being varied over the surface to control the spatial light distribution.

21. The light diffusing apparatus of claim 1 wherein said scattering element comprises a roughened surface of said polymer element, the surface being roughened in one or more discrete zones.

22. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles.

23. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles, said light scattering particles having a substantially different refractive index than said polymer element.

24. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles, said light scattering particles having a substantially different refractive index than said polymer element such as single core emulsion polymers, core-shell emulsion polymers, hollow core emulsion polymers, or mineral particles.

25. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles, said light scattering particles having a substantially different refractive index than said polymer element and comprising a particulate material of a size capable of scattering light predominantly at a 90°

angle.

26. The light diffusing apparatus of claim 1 wherein said polymer element comprises a polymer system with a matrix phase and a second phase and wherein said scattering element comprises said second phase resulting from phase separation during polymerization, cure, loss of solvent, exposure to nonsolvent, or change in temperature, said second phase having a substantially different refractive index than said matrix phase, said polymer system being a physical blend or copolymer.

27. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles, said light scattering particles having a substantially different refractive index than said polymer element and being dispersed throughout said polymer element.

28. The light diffusing apparatus of claim 1 wherein said scattering element comprises light scattering particles, said light scattering particles having a substantially different refractive index than said polymer element, said light scattering particles being localized in a coating layer over said polymer element.

29. The light diffusing apparatus of claim 1 wherein said scattering element comprises both a roughened surface of said polymer element and light scattering particles.

30. The light diffusing apparatus of claim 1 including an opaque layer over one or more discrete areas on the surface of said polymer element to control the spatial light distribution.

31. The light diffusing apparatus of claim 1 including a reflective layer over one or more discrete areas on the surface of said polymer element to control the spatial light distribution.

32. The light diffusing apparatus of claim 1 including a layer containing liquid crystalline core particles over one or more discrete areas on the surface of said polymer element to modulate the spatial light distribution by modulating the orientation of the liquid crystals to transmit or block light.

33. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said light transmitting polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape.

34. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said light transmitting polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, said secondary shape being a straight rod shape and said primary shape being a curved loop shape.

35. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said light transmitting polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, said secondary shape being a closed straight rod shape and said primary shape being an open “

grappling hook”

shape comprised of two or more prongs.

36. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said light transmitting polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the direction of light emission dynamically changing as said shape memory polymer element changes shape.

37. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said light transmitting polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the surrounding environment providing said heat.

38. The apparatus that guides light from a light source to a target area away from the light source of claim 1 wherein said polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the light from said light source being converted to said heat by absorption of the light by said shape memory polymer element.

39. The light diffusing apparatus of claim 1 wherein said polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the light from said light source being converted to said heat by light absorbing dye or light absorbing particles embedded in or coated on said shape memory polymer element, said light absorbing dye or light absorbing particles being uniformly dispersed.

40. The light diffusing apparatus of claim 1 wherein said polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the light from said light source being converted to said heat by light absorbing dye or light absorbing particles embedded in or coated on said shape memory polymer element, the concentration of said light absorbing dye or light absorbing particles being varied to control the spatial heat distribution.

41. The light diffusing apparatus of claim 1 wherein said polymer element comprises a shape memory polymer element, said shape memory polymer element comprising a solid shape memory polymer body or a porous foam shape memory polymer body or a porous foam shape memory polymer body about a solid shape memory polymer body, and wherein said shape memory polymer element can be formed into a primary or equilibrium shape, re-formed into a stable secondary or stressed shape, and actuated by heat to recover its primary shape, the light from said light source being converted to said heat by light absorbing dye or light absorbing particles embedded in or coated on said shape memory polymer element, said light absorbing dye or light absorbing particles being locally confined to permit localized heating.

42. An apparatus that guides light from a light source to a target area away from the light source, comprising:

an optical fiber, said optical fiber having a light transmitting core, a cladding layer about the core, a proximal end, and a distal end, the proximal end of the optical fiber being coupled to a the light source,

a light transmitting polymer element comprised of a shape memory polymer, said light transmitting polymer element comprised of a shape memory polymer operatively connected to the distal end of said optical fiber, and

wherein said light transmitting polymer element comprised of a shape memory polymer is comprised of a scattering light diffusing element incorporated with said light transmitting polymer element comprised of a shape memory polymer to diffuse light radially outward from said light transmitting polymer element.

43. A method of producing a light diffusing apparatus that diffuses light from an optical fiber, the optical fiber having a light transmitting core, a cladding layer about the core, a proximal end, and a distal end, the proximal end of the optical fiber being coupled to a light source, comprising the steps of:

forming a light transmitting polymer element adapted to be connected to the distal end of the optical fiber and

incorporating a scattering element with said polymer element to diffuse light radially outward from said polymer element.

44. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a solid polymer body.

45. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a porous foam polymer body and wherein said step of incorporating a scattering element with said polymer element comprises the inherent porous structure of said porous foam polymer body.

46. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a solid polymer body and a porous foam polymer body about the solid polymer body.

47. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a polymer coating over the exposed core at the distal end of the optical fiber, said cladding layer being removed to expose said core, said polymer coating having a refractive index equal to or slightly greater than that of the exposed core, said polymer coating being applied by dip-coating or other suitable means.

48. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a solid shape memory polymer.

49. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a porous foam shape memory polymer and wherein said step of incorporating a scattering element with said polymer element comprises the inherent porous structure of said porous foam shape memory polymer body.

50. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a solid shape memory polymer body and a porous foam shape memory polymer body about the solid shape memory polymer body.

51. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a cylindrical polymer body.

52. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming a spherical polymer body.

53. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises forming two or more polymer sections cascaded together, said polymer sections having different glass transition temperatures to provide variable axial stiffness along the length of said polymer element, said polymer sections being sequentially injection molded in a mold or bonded together under heated conditions.

54. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises creating a socket-epoxy joint to connect said polymer element to the optical fiber, said socket being created in the polymer by mechanical drilling, laser drilling, or other suitable means.

55. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises molding said polymer element around the optical fiber by injection molding said polymer element in a mold around the optical fiber.

56. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises pushing the distal end of the optical fiber into said polymer element under heated conditions.

57. The method of producing a light diffusing apparatus of claim 43 wherein said step of incorporating a scattering element with said polymer element comprises directly roughening the surface of said polymer element by bead (or other media) blasting, chemical etching, laser etching, or other abrasive means over the entire surface or in one or more discrete zones.

58. The method of producing a light diffusing apparatus of claim 43 wherein said step of incorporating a scattering element with said polymer element comprises injection molding said polymer element in a mold whose surface has been roughened by bead (or other media) blasting, chemical etching, laser etching, or other abrasive means over the entire surface or in one or more discrete zones.

59. The method of producing a light diffusing apparatus of claim 43 wherein said step of forming a polymer element comprises providing a polymer system with a matrix phase and a second phase and wherein said step of incorporating a scattering element with said polymer element comprises generating said second phase from phase separation during polymerization, cure, loss of solvent, exposure to nonsolvent, or change in temperature, said second phase having a substantially different refractive index than said matrix phase, said polymer system being a physical blend or copolymer.

60. The method of producing a light diffusing apparatus of claim 43 wherein said step of incorporating a scattering element with said polymer element, said polymer element having an initial liquid state and a final cured state, comprises adding light scattering particles to said polymer element in its initial liquid state such that said light scattering particles become dispersed throughout said polymer element in its final cured state.

61. The method of producing a light diffusing apparatus of claim 43 wherein said step of incorporating a scattering element with said polymer element comprises adding light scattering particles to a liquid polymer with refractive index equal to or slightly greater than that of said polymer element and coating said polymer element with said liquid polymer by dip-coating or other means such that said scattering particles are localized in a coating layer over said polymer element.