APPARATUS HAVING A PHOTONIC CRYSTAL
An apparatus, including a substrate, where at least a portion of the substrate has a convex surface, and a photonic crystal disposed over the convex surface. The photonic crystal is substantially conformal to at least a portion of the convex surface.
This application is related to co-pending and commonly assigned application Ser. No.______ filed on the same day herewith (attorney docket no. 20050418 by Herbert T. Etheridge III, Henry D. Lewis and Carol M. McConica and entitled “Apparatus Having a Photonic Crystal.”
BACKGROUND Description of the ArtAs the demand for cheaper and higher performance electronic devices continues to increase there is a growing need to develop higher yield lower cost manufacturing processes for electronic devices especially in the area of optical devices. In particular there is a demand for higher performance as well as improved efficiency in lighting technology.
Although incandescent lamps are inexpensive and the most widely utilized lighting technology in use today, they are also the most inefficient lighting source in regards to the amount of light generated per unit of energy consumed. An incandescent lamp works by heating a filament, typically tungsten, to a very high temperature so that it radiates in the visible portion of the electromagnetic spectrum. Unfortunately, at such high temperatures the filament radiates a considerable amount of energy in the non-visible infrared region of the electromagnetic spectrum.
If these problems persist, the continued growth and advancements in the use of opto-electronic devices, especially in the area of photonic crystals, in various electronic products, will be reduced. In areas like consumer electronics, the demand for cheaper, smaller, more reliable, and higher performance electronics constantly puts pressure on improving and optimizing performance of ever more complex and integrated devices. The ability to optimize lighting performance efficiency will open up a wide variety of applications that are currently either impractical, or are not cost effective.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is directed to various photonic structures utilizing colloidal crystals. The present invention includes a wide variety of photonic structures formed on, over or both on and over curved surfaces including, for example, wires and fiber optic cables. Photonic crystals, typically, are spatially periodic structures having useful electromagnetic wave properties, such as photonic band gaps. Photonic crystals, for example, having the proper lattice spacing, offer the potential of improving the luminous efficacy of an incandescent lamp by modifying the emissivity of the tungsten filament. Such a filament, incorporated into a photonic crystal or encircled or surrounded by a photonic crystal, would emit a substantial fraction of its radiation in the visible portion of the spectrum and little or no light in the non-visible portions such as the infrared portion of the electromagnetic spectrum. Since many filaments, including spirally wound filaments, utilized as incandescent sources have a large degree of cylindrical symmetry the ability to form photonic crystals on curved surfaces provides for simpler manufacturing processes to make incandescent light sources, having a lower cost, and a higher luminous efficiency. In addition, such a colloidal crystal may also be formed on an optical fiber to deter loss of light at desired wavelengths.
It should be noted that the drawings are not true to scale. Further, various elements have not been drawn to scale. Certain dimensions have been exaggerated in relation to other dimensions in order to provide a clearer illustration and understanding of the present invention. In particular, vertical and horizontal scales may differ and may vary from one drawing to another. In addition, although some of the embodiments illustrated herein are shown in two dimensional views with various regions having height and width, it should be clearly understood that these regions are illustrations of only a portion of a device that is actually a three dimensional structure. Accordingly, these regions will have three dimensions, including length, width, and height, when fabricated on an actual device.
Moreover, while the present invention is illustrated by various embodiments, it is not intended that these illustrations be a limitation on the scope or applicability of the present invention. Further, it is not intended that the embodiments of the present invention be limited to the physical structures illustrated. These structures are included to demonstrate the utility and application of the present invention to presently preferred embodiments.
An embodiment of apparatus 100 employing the present invention is illustrated, in a perspective view, in
An alternate embodiment of the present invention is shown in a perspective view in
An alternate embodiment of the present invention is shown in a perspective view in
An alternate embodiment of the present invention is shown in a perspective view in
The colloidal crystals shown in
For those embodiments utilizing an inverse opal crystal structure a variety of deposition techniques may be utilized to fill the interstitial volume formed between the spheres such as atomic layer deposition (ALD), chemical vapor deposition (CVD), electro-deposition, and electroless deposition and other wet infiltration methods. An exemplary technique utilizes atomic layer deposition to fill or infiltrate the interstitial volume of the colloidal crystal. In one embodiment a tungsten inverse opal structure may be generated utilizing alternating exposures of the colloidal crystal to tungsten hexafluoride (WF6) and silicon hydride (e.g. SiH4, Si2H6, Si3H8 and mixtures of various silicon hydrides). The tungsten film growth may be achieved utilizing an alternating sequence of exposures of WF6 and Si2H6 in the temperature range from about 100° C. to about 400° C. It is believed that the disilane reactant serves a sacrificial role to strip fluorine from tungsten limiting the incorporation of silicon into the film; however, the present invention is not limited to such a mechanism. Other chemistries also may be utilized such as tungsten hexacarbonyl as a tungsten precursor material and boron compounds such as a boron hydride as a reducing agent. In alternate embodiments, other silicon hydrides also may be utilized. In still other embodiments a wide range of inorganic materials also may be utilized. Tungsten nitride, titanium dioxide, graphite, diamond, tungsten carbide, hafnium carbide, and indium phosphide are just a few examples. After the interstitial volume in the crystal is filled or substantially filled the silica spheres may then be removed by soaking in a aqueous hydrofluoric acid solution (i.e. typically about 2 weight percent) to form inverse opal photonic crystal 604 as illustrated in
Claims
1. An apparatus, comprising:
- a substrate, wherein at least a portion of said substrate has a convex surface; and
- a photonic crystal disposed over said convex surface, wherein said photonic crystal is substantially conformal to at least a portion of said convex surface.
2. An apparatus, comprising:
- a substrate, wherein at least a portion of said substrate has a convex surface: and
- a colloidal photonic crystal disposed over said convex surface, wherein said colloidal crystal is substantially conformal to at least a portion of said convex surface.
3. The apparatus in accordance with claim 2, wherein said colloidal crystal further comprises:
- a plurality of first spheres having a first diameter; and
- a plurality of second spheres having a second diameter.
4. The apparatus in accordance with claim 3, wherein said colloidal crystal further comprises a first layer having said plurality of first spheres, and a second layer having said plurality of second spheres.
5. The apparatus in accordance with claim 3, wherein said colloidal crystal further comprises a first layer having said plurality of first spheres and an n th layer having said plurality of second spheres, wherein n is an integer greater than one.
6. The apparatus in accordance with claim 3, wherein said colloidal crystal further comprises a first layer having said plurality of first spheres alternating with a second layer having said plurality of second spheres.
7. The apparatus in accordance with claim 3, wherein said colloidal crystal further comprises a first group of layers having said plurality of first spheres alternating with a second group of layers having said plurality of second spheres.
8. The apparatus in accordance with claim 3, wherein said plurality of first spheres and said plurality of second spheres form a binary colloidal crystal.
9. The apparatus in accordance with claim 2, wherein said colloidal crystal further comprises metal spheres.
10. The apparatus in accordance with claim 2, wherein said colloidal crystal further comprises spheres having a differential solubility over an infiltration material.
11. The apparatus in accordance with claim 2, wherein said colloidal photonic crystal further comprises a layer of spheres.
12. The apparatus in accordance with claim 2, wherein said colloidal photonic crystal further comprises a photonic band gap crystal.
13. The apparatus in accordance with claim 2, wherein said colloidal photonic crystal further comprises a spatially periodic structure.
14. An apparatus, comprising:
- a substrate, wherein at least a portion of said substrate has a convex surface; and
- an inverse opal crystal structure disposed over said convex surface, wherein said inverse opal crystal structure is substantially conformal to at least a portion of said convex surface.
15. The apparatus in accordance with claim 14, wherein said inverse opal crystal structure includes a refractory metal.
16. The apparats in accordance with claim 2, wherein said convex surface further comprises a substantially cylindrically shaped surface.
17. The apparatus in accordance with claim 16, wherein said substantially cylindrically shaped surface further comprises a filament.
18. The apparatus in accordance with claim 17, wherein said filament further comprises a metal wire.
19. The apparatus in accordance with claim 17, wherein said metal wire further comprises a refractory metal wire.
20. The apparatus in accordance with claim 17, wherein said filament further comprises an optical fiber.
21. The apparatus in accordance with claim 16, wherein said substantially cylindrically shaped surface further comprises a tubularly-shaped structure having an outer surface, wherein said colloidal photonic crystal is disposed over and conformal to at least a portion of said outer surface of said tube.
22. The apparatus in accordance with claim 21, wherein said tubularly shaped substrate is substantially optically transparent in the visible portion of the electromagnetic spectrum.
23. The apparatus in accordance with claim 21, further comprising a metal wire disposed at least partially within said tubularly shaped substrate.
24. The apparatus in accordance with claim 23, wherein said metal wire further comprises a spirally wound metal wire filament.
25. The apparatus in accordance with claim 24, wherein said spirally wound metal wire filament further comprises a photonic crystal conformal to and disposed on at least a portion of said spirally wound metal wire filament.
26. The apparatus in accordance with claim 2, wherein said convex surface forms at least a portion of an optical component such as a lens.
27. The apparatus in accordance with claim 26, where in said lens further comprises a rod lens.
28. The apparatus in accordance with claim 2, wherein said substrate further comprises a tubularly shaped substrate having at least a portion of an external surface of said tubularly shaped substrate forming said convex surface.
29. The apparatus in accordance with claim 28, wherein said colloidal photonic crystal is disposed over and conformal to said external surface of said tubularly shaped substrate.
30. The apparatus in accordance with claim 29, further comprising a metal wire disposed at least partially within said tubularly shaped substrate.
31. The apparatus in accordance with claim 30, wherein said metal wire further comprises a spirally wound metal wire filament.
32. The apparatus in accordance with claim 31, wherein said spirally wound metal wire filament further comprises a photonic crystal conformal to and disposed on at least a portion of said spirally wound metal wire filament.
33. The apparatus in accordance with claim 2, wherein said substrate further comprises a rod-like substrate.
34. The apparatus in accordance with claim 33, wherein said rod-like structure further comprises a filament.
35. The apparatus in accordance with claim 34, wherein said filament further comprises a metal wire.
36. The apparatus in accordance with claim 35, wherein said metal wire further comprises a refractory metal wire.
37. The apparatus in accordance with claim 34, wherein said metal wire further comprises a spirally wound metal wire.
38. The apparatus in accordance with claim 37, wherein said spirally wound metal wire further comprises a photonic crystal conformal to and disposed on at least a portion of said spirally wound metal wire.
39. The apparatus in accordance with claim 2, wherein said substrate further comprises said substrate having an external closed surface.
40. The apparatus in accordance with claim 2, wherein said substrate further comprises a conically-shaped substrate.
41. The apparatus in accordance with claim 2, wherein
- said substrate further comprises a spherically-shaped substrate.
42. The apparatus in accordance with claim 2, wherein said substrate further comprises cylindrically-shaped substrate having a cylindrical axis, wherein said colloidal photonic crystal substantially encircles said cylindrical axis.
43. The apparatus in accordance with claim 42, further comprising an inner photonic crystal disposed on an internal surface of said cylindrically shaped substrate, wherein said inner photonic crystal substantially encircles said cylindrical axis.
44. The apparatus in accordance with claim 42, further comprising a metal wire disposed in said cylindrically-shaped substrate and substantially coaxial with said cylindrical axis.
45. A method of manufacturing a photonic crystal, comprising forming an inverse opal photonic crystal over at least a portion of a convex surface, wherein the inverse opal photonic crystal is conformal to at least a portion of said convex surface.
46. A method of manufacturing an apparatus, comprising forming at least one layer of spheres over a convex surface of a substrate, wherein said at least one layer of spheres is conformal to said convex surface.
47. The method in accordance with claim 46, forming at least one layer of spheres further comprises forming multiple layers of spheres over and conformal to said convex surface of said substrate, wherein said multiple layers include void spaces between said spheres.
48. A method of manufacturing a photonic apparatus, further comprising:
- forming two or more layers of spheres over and conformal to a convex surface of a substrate; and
- forming a second material in said void spaces.
49. The method in accordance with claim 48, further comprising substantially filling said void spaces with said second material.
50. The method in accordance with claim 49, further comprising removing said spheres to form an inverse opal crystal.
51. The method in accordance with claim 48, wherein said spheres have a sphere dielectric constant and said second material has a dielectric constant different from said sphere dielectric constant.
52. The method in accordance with claim 48, further comprising immersing said convex surface in a mixture of spheres and a solvent.
53. The method in accordance with claim 52, wherein immersing said convex surface further comprises immersing said convex surface so that a long axis of said convex surface is substantially perpendicular to a meniscus formed by said mixture.
54. The method in accordance with claim 48, further comprising suspending said convex surface in a mixture of spheres and a solvent.
55. The method in accordance with claim 54, wherein suspending said convex surface further comprises suspending said convex surface so that a long axis of said convex surface is substantially perpendicular to a meniscus formed by said mixture.
56. The method in accordance with claim 48, further comprising cleaning said convex surface.
57. The method in accordance with claim 48, wherein forming at least one layer of spheres further comprises forming at least one layer of spheres utilizing a mixture of spheres in a solvent.
58. The method in accordance with claim 57, further comprising removing said solvent.
59. The method in accordance with claim 58, wherein removing said solvent further comprises evaporating said solvent.
60. The method in accordance with claim 48, further comprising forming a sacrificial layer over at least a portion of a substrate that forms said convex surface.
61. The method in accordance with claim 48, further comprising etching a substrate that forms said convex surface.
62. A method of using an inverse opal photonic crystal, comprising transmitting at least a portion of the electromagnetic spectrum through a convex surface forming at least a portion of the inverse opal photonic crystal.
63. The method in accordance with claim 62, further comprising heating an incandescent filament, wherein at least a portion of the inverse opal photonic crystal encircles said incandescent filament.
64. The method in accordance with claim 63, wherein the inverse opal photonic crystal is disposed on said incandescent filament.
65. The method in accordance with claim 64, wherein said incandescent filament includes a refractory metal.
66. The method in accordance with claim 63, wherein the inverse opal photonic crystal further comprises a tubularly-shaped inverse opal photonic crystal, and said incandescent filament is disposed within said tubularly-shaped inverse opal photonic crystal.
67. A method of using a photonic crystal, comprising heating an incandescent filament disposed within a tubularly-shaped photonic crystal substantially encircling said incandescent filament.
68. An apparatus, comprising:
- substrate, wherein at least a portion of said substrate has a convex surface, and
- means for forming a colloidal photonic crystal disposed over and substantially conformal to said convex surface.
69. The apparatus in accordance with claim 68, wherein said means for forming said colloidal photonic crystal further comprises forming a polymeric colloidal crystal.
70. The apparatus in accordance with claim 68, wherein said means for forming said colloidal photonic crystal further comprises forming a photonic band gap crystal.
71. The apparatus in accordance with claim 70, wherein said means for forming said colloidal photonic crystal further comprises forming a refractory metal colloidal photonic crystal.
Type: Application
Filed: Jan 28, 2005
Publication Date: Aug 3, 2006
Inventors: Herbert Etheridge (Corvallis, OR), Henry Lewis (Corvallis, OR), Carol McConica (Corvallis, OR)
Application Number: 11/046,586
International Classification: G02F 1/00 (20060101);