Light recycling systems and methods

• US 20080128727A1
• Filed: 05/17/2007
• Published: 06/05/2008
• Est. Priority Date: 09/10/2004
• Status: Abandoned Application

• Current Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Original Assignee: Luminus Devices Incorporated (Sanan Optoelectronics Company Limited)
• Inventors: Nemchuk, Nikolay I., Lim, Michael, Pokrovskiy, Alexander L., Erchak, Alexei A.
• Application Number:
  US11/804,207
• Publication Number:
  US 20080128727A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/13362 providing polarized light, e.g. by converting a polarisation component into another one
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

Light-emitting devices and/or systems are described. In some embodiments, light-emitting devices and/or systems can recycle at least some light generated by a light-generating region of the light-emitting device. In one embodiment, a light-emitting system comprises a light-emitting device including a light-generating region, a polarization manipulation region that alters a polarization state of at least some light from a first polarization state to a second polarization state, wherein the polarization manipulation region comprises a plurality of features, and a feedback element that returns, to the polarization manipulation region, at least some light having the first polarization state and outputs at least some light having the second polarization state, wherein the polarization manipulation region is disposed at least partially between the light-generating region and the feedback element.

Claims

1. A light-emitting system comprising:

a light-emitting device including a light-generating region;

a polarization manipulation region that alters a polarization state of at least some light from a first polarization state to a second polarization state, wherein the polarization manipulation region comprises a plurality of features; and

a feedback element that returns, to the polarization manipulation region, at least some light having the first polarization state and outputs at least some light having the second polarization state,

wherein the polarization manipulation region is disposed at least partially between the light-generating region and the feedback element.

2. The light-emitting system of claim 1, wherein the plurality of features comprise a roughened surface.

3. The light-emitting system of claim 1, wherein the plurality of features comprise a region having a dielectric function that varies spatially according to a pattern.

4. The light-emitting system of claim 3, wherein the pattern comprises a non-periodic pattern.

5. The light-emitting system of claim 3, wherein the pattern comprises a non-periodic pattern.

6. The light-emitting system of claim 3, wherein the region having the dielectric function that varies spatially according to the pattern allows generated light to pass therethrough.

7. The light-emitting system of claim 3, wherein the region having the dielectric function that varies spatially according to the pattern comprise a plurality of holes.

8. The light-emitting system of claim 7, wherein the plurality of holes have a size of less than 1 micron.

9. The light-emitting system of claim 1, wherein the light-emitting device comprises a light-emitting diode.

10. The light-emitting system of claim 1, wherein the plurality of features comprise a semiconductor layer.

11. The light-emitting system of claim 10, wherein the light-generating region comprises a semiconductor layer.

12. The light-emitting system of claim 1, wherein the light-emitting device comprises the polarization manipulation region.

13. The light-emitting system of claim 1, wherein the light-emitting device comprises the feedback element.

14. The light-emitting system of claim 1, wherein the polarization manipulation region is substantially disposed between the light-generating region and the feedback element.

15. The light-emitting system of claim 1, wherein the polarization manipulation region is partially disposed under at least a portion of the light-generating region.

16. The light-emitting system of claim 1, wherein the feedback element is separated from the polarization manipulation region.

17. The light-emitting system of claim 16, wherein a distance between the feedback element and the polarization manipulation region is greater than a peak wavelength of the generated light and less than 5 times the peak wavelength of the generated light.

18. The light-emitting system of claim 16, wherein a distance between the feedback element and the polarization manipulation region is less than 2.5 microns.

19. The light-emitting system of claim 16, wherein the feedback element is separated from the polarization manipulation region by a material region having a refractive index of less than 1.6.

20. The light-emitting system of claim 19, wherein the light-emitting device is a GaN-based light-emitting device.

21. The light-emitting system of claim 16, wherein the feedback element is separated from the polarization manipulation region by a gas and/or a vacuum.

22. The light-emitting system of claim 16, wherein the feedback element is separated from the polarization manipulation region by a medium including a wavelength converting material.

23. The light-emitting system of claim 22, further comprising a wavelength filter disposed between the wavelength converting material and the light-generating region.

24. The light-emitting system of claim 1, wherein the feedback element returns, to the manipulation region, substantially all light having the first polarization state and outputs substantially all light having the second polarization state.

25. The light-emitting system of claim 1, wherein the feedback element comprises at least one reflective polarizer.

26. The light-emitting system of claim 1, wherein the feedback element comprises at least one wire grid polarizer.

27. The light-emitting system of claim 26, wherein the polarization manipulation region comprises a plurality of reflective regions disposed over at least a portion of the light-generating region.

28. The light-emitting system of claim 1, wherein the manipulation region further comprises at least one phase retarder.

29. The light-emitting system of claim 1, wherein the manipulation region further comprises at least one quarter wave plate.

30. The light-emitting system of claim 1, wherein the manipulation region further comprises at least one anisotropic material.

31. A light-emitting system comprising:

a light-emitting device including a light-generating region;

a manipulation region that alters a characteristic state of at least some light from a first characteristic state to a second characteristic state, wherein the manipulation region comprises a plurality of features; and

a feedback element that returns, to the manipulation region, at least some light having the first characteristic state and outputs at least some light having the second characteristic state,

wherein the manipulation region is disposed at least partially between the light-generating region and the feedback element.

32. The light-emitting system of claim 31, wherein the characteristic is polarization.

33. The light-emitting system of claim 31, wherein the characteristic is propagation direction.

34. The light-emitting system of claim 31, wherein the characteristic is wavelength.

35. The light-emitting system of claim 31, wherein the plurality of features comprise a region having a dielectric function that varies spatially according to a pattern.

36. The light-emitting system of claim 31, wherein the plurality of features comprise a roughened surface.

37. A method of making a light-emitting system, the method comprising:

providing a light-emitting device including a light-generating region;

providing a polarization manipulation region that alters a polarization state of at least some light from a first polarization state to a second polarization state, wherein the polarization manipulation region comprises a plurality of features; and

providing a feedback element that returns, to the polarization manipulation region, at least some light having the first polarization state and outputs at least some light having the second polarization state,

wherein the polarization manipulation region is disposed at least partially between the light-generating region and the feedback element.

38. A method of making a light-emitting system, the method comprising:

providing a light-emitting device including a light-generating region;

providing a manipulation region that alters a characteristic state of at least some light from a first characteristic state to a second characteristic state, wherein the manipulation region comprises a plurality of features; and

providing a feedback element that returns, to the manipulation region, at least some light having the first characteristic state and outputs at least some light having the second characteristic state,

wherein the manipulation region is disposed at least partially between the light-generating region and the feedback element.