Waveguide sheet containing in-coupling, propagation, and out-coupling regions
In one aspect, an illumination structure includes a substantially non-fiber waveguide, which itself includes a discrete in-coupling region for receiving light, a discrete propagation region for propagating light, and a discrete out-coupling region for emitting light.
1. An illumination structure comprising:
a substantially non-fiber waveguide, the waveguide comprising:
a discrete in-coupling region for receiving light and comprising an optical element disposed therewithin,
a discrete propagation region for propagating light and that is substantially free of the optical element, and
a discrete out-coupling region for emitting light, the in-coupling, propagation, and out-coupling regions being spatially distinct, light entering the in-coupling region being substantially retained within the waveguide for emission from the out-coupling region.
2. The illumination structure of claim 1 , further comprising:
a first cladding layer disposed over a top surface of the waveguide; and
a second cladding layer disposed beneath a bottom surface of the waveguide.
3. The illumination structure of claim 1 , wherein the optical element comprises a plurality of scattering particles.
4. The illumination structure of claim 1 , wherein the propagation region is substantially free of scattering particles.
5. The illumination structure of claim 1 , wherein the out-coupling region comprises a plurality of scattering particles.
6. The illumination structure of claim 5 , wherein the scattering particles have a concentration that varies across at least one dimension of the out-coupling region.
7. The illumination structure of claim 6 , wherein the concentration of scattering particles increases with distance from the in-coupling region.
8. The illumination structure of claim 1 , wherein the out-coupling region comprises a plurality of core structures, at least some of which comprise a plurality of scattering particles, and wherein at least one of a size, a concentration, or a type of the scattering particles varies among at least two of the core structures.
9. The illumination structure of claim 8 , wherein, in a direction perpendicular to a general direction of light propagation therethrough, there is substantially no overlap between individual core structures.
10. The illumination structure of claim 8 , wherein each of the core structures has a substantially quadrilateral cross-sectional area.
11. The illumination structure of claim 10 , wherein the cross-sectional area is substantially rectangular.
12. The illumination structure of claim 1 , further comprising means for emitting light disposed proximate the in-coupling region.
13. The illumination structure of claim 1 , further comprising means for emitting light disposed within the waveguide.
14. The illumination structure of claim 1 , further comprising a reflector disposed proximate a surface of the in-coupling region.
15. The illumination structure of claim 1 , wherein the waveguide is substantially planar.
16. The illumination structure of claim 1 , wherein an optical mean free path of light in the propagation region is substantially constant, and an optical mean free path of light in the out-coupling region varies substantially monotonically.
17. A method of producing light, the method comprising:
providing a substantially non-fiber waveguide comprising:
a discrete in-coupling region for receiving light comprising an optical element disposed therewithin,
a discrete propagation region for propagating light and that is substantially free of the optical element, and
a discrete out-coupling region for emitting light; and
emitting light proximate the in-coupling region, whereby the light propagates through the propagation region with substantially no emission therefrom into the out-coupling region, and is emitted from the out-coupling region.
18. The illumination structure of claim 1 , wherein the optical element comprises a microlens.
19. The illumination structure of claim 1 , wherein the optical element comprises an optical funnel.
20. The illumination structure of claim 1 , wherein the in-coupling region receives light entering in a first direction, the propagation region propagates light in a second direction perpendicular to the first direction, and the out-coupling region emits light in a third direction perpendicular to the second direction.
21. The illumination structure of claim 13 , wherein the means for emitting light consists essentially of a bare-die light-emitting diode.
22. The method of claim 17 , wherein the optical element comprises a plurality of scattering particles.
23. The method of claim 17 , wherein the optical element comprises a microlens.
24. The method of claim 17 , wherein the optical element comprises an optical funnel.
25. The method of claim 17 , wherein the in-coupling region receives light entering in a first direction, the propagation region propagates light in a second direction perpendicular to the first direction, and the out-coupling region emits light in a third direction perpendicular to the second direction.