WAVEGUIDE WITH NANOPARTICLE INDUCED REFRACTIVE INDEX GRADIENT

• US 20040071422A1
• Filed: 10/11/2002
• Published: 04/15/2004
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: SKC Haas Display Films Co., Ltd. (Dow, Inc.)
• Original Assignee: Eastman Kodak Company
• Inventors: Majumdar, Debasis, Dontula, Narasimharao, Aylward, Peter T., Miller, Anne M.
• Granted Patent: US 6,728,456 B1
• Time in Patent Office: Days
• US Class Current: 385/124
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 1/046 characterised by the core material
• CPC Class Codes: G02B 1/048 characterised by the cladding material
• CPC Class Codes: G02B 2006/12095 Graded
• CPC Class Codes: G02B 6/02033 Core or cladding made from organic material, e.g. polymeric material G02B1/04 takes precedence
• CPC Class Codes: G02B 6/02038 with core or cladding having graded refractive index
• CPC Class Codes: G02B 6/0229 characterised by nanostructures, i.e. structures of size less than 100 nm, e.g. quantum dots
• CPC Class Codes: G02B 6/1221 made from organic materials

Abstract

An optical element comprising an elongated channel for light travel comprising a light transmitting polymeric central core and further comprising multilayer particles, wherein a majority of the particles have both a longest dimension less than 1 micrometer and an aspect ratio of longest to smallest dimension of from 1000:1, to 10:1, wherein the particles are arranged in a concentration differential in at least a portion of a plane normal to the length of the channel so as to create a refractive index gradient in that plane.

Claims

1. An optical component comprising an elongated channel for light travel comprising a light transmitting polymeric central core and further comprising multilayer particles, wherein a majority of the particles have both a longest dimension less than 1 micrometer and an aspect ratio of longest to smallest dimension of from 1000:

1 to 10;

1, wherein the particles are arranged in a concentration differential in at least a portion of a plane normal to the length of the channel so as to create a refractive index gradient in that plane.

2. The optical component of claim 1 wherein the central core comprises a planar shape.

3. The optical component of claim 2 wherein said central core contains layered particles in a concentration gradient so as to provide a decreasing differential refractive index from the center to the outer edges of the central core.

4. The optical component of claim 2 that further comprises a clad layer on one or both sides of the central core.

5. The optical component of claim 3 wherein said clad layer is opaque.

7. The optical component of claim 4 wherein said clad layer is light absorbing.

8. The optical component of claim 7 wherein said clad layer is black.

9. The optical component of claim 4 wherein said clad layer further comprises an adhesive.

10. The optical component of claim 1 wherein the central core is arcuate.

11. The optical component of claim 1 wherein the central core is cylinder shaped.

12. The optical component of claim 11 wherein said central core is a fiber.

13. The optical component of claim 11 wherein said cylinder has at least one annular shaped clad layer surrounding the cylinder.

14. The optical component of claim 1 wherein the central core is shaped like a lens.

15. The optical component of claim 14 wherein said lens-like shape is convex.

16. The optical component of claim 14 wherein said lens-like shape is concave.

17. The optical component of claim 14 wherein the central core comprises multiple lenses.

18. The optical component of claim 1 wherein the central core is a lens array.

19. The optical component of claim 18 wherein said lens array has a geometric shape.

20. The optical component of claim 1 wherein said layered particles are disposed in said central core in a weight percent of between 0 to 90%.

21. The optical component of claim 1 wherein said layered particles form a concentration gradient with increasing concentration with distance from the center of the light channel in a plane of normal to the direction of the length of the channel.

22. The optical component of claim 1 wherein said concentration gradient represents a linear rate of change.

23. The optical component of claim 1 wherein said concentration gradient represents an exponential rate of change.

24. The optical component of claim 1 wherein said concentration gradient decreases linearly from the central axis to the outer edges.

25. The optical component of claim 1 wherein the multilayer particles have an average thickness of between 0.5 to 10 nm.

26. The optical component of claim 1 wherein the layered particles have an aspect ratio of the largest to smallest particle dimension of between 10:

1 and 1000;

1.

27. The optical component of claim 1 wherein said multilayer particles comprise a hydrotalcite.

28. The optical component of claim 1 wherein said multilayer particles comprise a phyllosilicate.

29. The optical component of claim 28 wherein said phyllosilicate comprises a smectite.

30. The optical component of claim 29 wherein said smectite comprises montmorillonite.

31. The optical component of claim 30 wherein said montmorillonite comprises aluminum silicate.

32. The optical component of claim 29 wherein said smectite comprises hectorite.

33. The optical component of claim 32 wherein said hectorite is fluorinated.

34. The optical component of claim 32 wherein said hectorite comprises magnesium silicate.

35. The optical component of claim 29 wherein said smectite is synthetic.

36. The optical component of claim 29 wherein said smectite is organically modified.

37. The optical component of claim 29 wherein said smectite is fluorinated.

38. The optical component of claim 1 wherein said polymeric channel has a thickness of between 0.5-1000 micrometers.

39. The optical component of claim 1 wherein said gradient is formed by a series of step changes with a refractive index change of less than 0.01 per step.

40. A method of guiding light comprising allowing light to enter the waveguide of claim 1.

41. A display screen comprising the waveguide of claim 1.

6. The optical component of laim 3 wherein said clad layer has a lower refractive index than said central core.