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 comprising an optical element disposed therewithin, the waveguide comprising:
a discrete in-coupling region for receiving light,
a discrete propagation region for propagating light, light entering the propagation region from the in-coupling region having a predetermined optical profile comprising at least one of (i) substantial uniformity of color profile or (ii) substantial uniformity of intensity, 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 , wherein the propagation region is substantially free of the optical element.
3. The illumination structure of claim 1 , wherein the optical element comprises a microlens.
4. The illumination structure of claim 1 , wherein the optical element comprises a plurality of photoluminescent particles.
5. The illumination structure of claim 1 , wherein the predetermined optical profile comprises substantial uniformity of color profile, the color profile comprising white light.
6. The illumination structure of claim 1 , wherein an optical mean free path of light in the in-coupling region is different from an optical mean free path of light in the propagation region.
7. The illumination structure of claim 6 , wherein the optical mean free path of light in the in-coupling region is less than the optical mean free path of light in the propagation region.
8. The illumination structure of claim 1 , wherein the out-coupling region comprises the optical element.
9. The illumination structure of claim 8 , wherein the optical element comprises a plurality of hemispheres.
10. The illumination structure of claim 9 , wherein the hemispheres have a concentration that varies across at least one dimension of the out-coupling region.
11. The illumination structure of claim 10 , wherein the concentration of the hemispheres increases with distance from the in-coupling region.
12. The illumination structure of claim 9 , wherein the hemispheres have a dimension that varies across at least one dimension of the out-coupling region.
13. The illumination structure of claim 9 , wherein the out-coupling region comprises a plurality of core structures, at least some of which comprise hemispheres, and wherein at least one of a size, a concentration, or a type of the hemispheres varies among at least two of the core structures.
14. The illumination structure of claim 9 , wherein the in-coupling region comprises a microlens.
15. The illumination structure of claim 1 , further comprising means for emitting light disposed proximate the in-coupling region.
16. The illumination structure of claim 1 , further comprising means for emitting light disposed within the waveguide.
17. The illumination structure of claim 16 , wherein the means for emitting light consists essentially of a bare-die light-emitting diode.
18. The illumination structure of claim 1 , further comprising a reflector disposed proximate a surface of the in-coupling region.
19. The illumination structure of claim 1 , wherein the waveguide is substantially planar.
20. 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.
21. 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.
22. A method of producing light, the method comprising:
providing a substantially non-fiber waveguide comprising an optical element disposed therewithin, the waveguide comprising:
a discrete in-coupling region for receiving light,
a discrete propagation region for propagating light, and
a discrete out-coupling region for emitting light; and
emitting light proximate the in-coupling region, whereby the light (a) exits the in-coupling region and enters the propagation region having a predetermined optical profile comprising at least one of (i) substantial uniformity of color profile or (ii) substantial uniformity of intensity, and (b) is emitted from the out-coupling region.
23. The method of claim 22 , wherein the predetermined optical profile comprises substantial uniformity of color profile, the color profile comprising white light.
24. The method of claim 22 , wherein the light propagates through the propagation region with substantially no emission therefrom into the out-coupling region.
25. The method of claim 22 , 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.
26. The method of claim 25 , wherein the out-coupling region emits light in a third direction perpendicular to the second direction.