DEVICE AND METHOD FOR REDUCING ETENDUE IN A DIODE LASER

• US 20090168186A1
• Filed: 09/08/2008
• Published: 07/02/2009
• Est. Priority Date: 09/07/2007
• Status: Abandoned Application

• Current Assignee: Evans & Sutherland Computer Corp. (Elevate Entertainment, Inc.)
• Original Assignee: Evans & Sutherland Computer Corp. (Elevate Entertainment, Inc.)
• Inventors: Christensen, Robert, Tanner, Allen, Williams, Forrest
• Application Number:
  US12/206,582
• Publication Number:
  US 20090168186A1
• Time in Patent Office: Days
• US Class Current: 359/621
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 19/009 for use with infrared radiation
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence

Abstract

An optical assembly for reducing the etendue of a diode laser light source having a plurality of laser light emitters. The optical assembly comprises a first optical device for collimating beams of light emitted from the emitters of the diode laser. A second optical device spatially shifts a portion of the collimated light beams emitted from the diode laser to thereby reduce gaps or dark space between the beams. A third optical device focuses all of the light beams onto a surface, such as a surface of a light modulation surface.

Claims

1. An apparatus for reducing etendue of a laser light source having a plurality of emitters grouped into a first group of emitters and a second group of emitters, said apparatus comprising:

a first optical device for collimating light emitted from the plurality of emitters;

a second optical device for reducing a spatial separation between light from the first group of emitters and light from the second group of emitters; and

a third optical device for focusing the light from the first group of emitters and the second group of emitters.

2. The apparatus of claim 1, wherein the first optical device comprises a plurality of lenses.

3. The apparatus of claim 1, wherein the first optical device comprises a wavelength-dependent coating.

4. The apparatus of claim 1, wherein the first optical device is dynamically adjustable.

5. The apparatus of claim 1, wherein the second optical device comprises at least one reflecting surface.

6. The apparatus of claim 1, wherein the second optical device comprises two reflecting surfaces.

7. The apparatus of claim 5, wherein the at least one reflecting surface comprises a wavelength-dependent coating.

8. The apparatus of claim 6, wherein the two reflecting surfaces each comprises a wavelength-dependent coating.

9. The apparatus of claim 1, wherein the third optical device comprises a lens.

10. The apparatus of claim 1, wherein the third optical device focuses light from the first group of emitters and the second group of emitters into a line image.

11. The apparatus of claim 1, further comprising a light modulation device, and wherein the third optical device focuses the light from the emitters onto the light modulation device.

12. An apparatus for reducing etendue of a light source having a plurality of spatially separated emitters, said apparatus comprising:

a first optical device for shaping light emitted from the emitters;

a second optical device for reducing a spatial separation between the shaped light; and

a third optical device for focusing the light from the emitters onto a surface.

13. The apparatus of claim 12, wherein the first optical device comprises at least one lens.

14. The apparatus of claim 12, wherein the first optical device comprises a wavelength-dependent coating.

15. The apparatus of claim 12, wherein the first optical device is dynamically adjustable.

16. The apparatus of claim 12, wherein the second optical device comprises at least one reflecting surface.

17. The apparatus of claim 12, wherein the second optical device comprises two reflecting surfaces.

18. The apparatus of claim 16, wherein the at least one reflecting surface comprises a wavelength-dependent coating.

19. The apparatus of claim 17, wherein the two reflecting surfaces each comprises a wavelength-dependent coating.

20. The apparatus of claim 12, wherein the third optical device comprises a lens.

21. The apparatus of claim 12, wherein the third optical device focuses the light from the emitters into a line image.

22. The apparatus of claim 21, further comprising a light modulation device, and wherein the third optical device focuses the line image onto a surface of the light modulation device.

23. A method for reducing etendue of a light source having a plurality of emitters grouped into a first group of emitters and second group of emitters, said method comprising the steps of:

collimating light emitted from each of the plurality of emitters;

spatially shifting light to thereby reduce a spatial separation between light emitted from the first group of emitters and light emitted from the second group of emitters; and

focusing the light from the first group of emitters and light emitted from the second group of emitters onto a surface.

24. The method of claim 23, wherein the step of collimating the light emitted from each of the plurality of emitters comprises the step of using spherical lenses to collimate the light.

25. The method of claim 24, wherein each of the spherical lenses comprises a wavelength-dependent coating.

26. The method of claim 23, wherein the step of spatially shifting light comprises the step of using at least one reflecting surface.

27. The method of claim 23, wherein the step of spatially shifting light comprises the step of using at least two reflecting surfaces.

28. The method of claim 23, wherein the step of focusing the light comprises the step of using a lens.

29. The method of claim 28, wherein the lens is a type selected from the groups consisting of cylindrical lenses, spherical lenses and anamorphic lenses.

30. The method of claim 28, wherein the lens includes a coating optimized for use with a single wavelength of light.

31. The method of claim 23, wherein the method is used for medical purposes.

32. The method of claim 23, wherein the method is used for welding purposes.

33. The method of claim 23, wherein the method is used in a projection system.

34. A light emitting apparatus having a reduced etendue, the apparatus comprising:

a laser light source having a plurality of emitters grouped into a first group of emitters and a second group of emitters;

a first optical device for collimating light emitted from the plurality of emitters;

a second optical device for reducing spatial separation between light emitted from the first group of emitters and light emitted from the second group of emitters; and

a third optical device for focusing the light from the first group of emitters and the light from the second group of emitters.

35. The apparatus of claim 34, wherein said plurality of emitters comprise diode lasers.

36. The apparatus of claim 34, wherein said first group of emitters and said second group of emitters form an array.

37. The apparatus of claim 36, wherein said array is a two-dimensional array.

38. The apparatus of claim 34, wherein the emitters are semiconductor devices.

39. The apparatus of claim 34, further comprising a light modulation device, and wherein said third optical device focuses a line image onto the light modulation device.

40. The apparatus of claim 34, wherein said plurality of emitters are disposed on a chip.

41. An optical system having a plurality of light sources, each of the plurality of light sources comprising a plurality of emitters, said optical system comprising:

a plurality of optical systems, each of the plurality of optical systems being associated with one of the plurality of light sources;

wherein each optical system is operable to reduce an etendue of its associated one of the plurality of light sources.

42. The optical system of claim 41, wherein each optical system comprises a first optical device for reducing gaps between beams of light emitted from the emitters of its associated one of the plurality of light sources.

43. The optical system of claim 42, wherein each optical system comprises lenses for collimating light from each of the emitters of its associated one of the plurality of light sources.

44. An apparatus for reducing etendue of a light source having a plurality of emitters, said apparatus comprising:

a first optical device for shaping light from the emitters;

a second optical device for spatially shifting light from the emitters; and

a third optical device for further shaping the light from the emitters.

45. The apparatus of claim 44, wherein the light source is a diode laser.

46. The apparatus of claim 44, wherein the light source emits visible light.

47. The apparatus of claim 44, wherein the light source emits infrared light.

48. The apparatus of claim 44, wherein the light source is coherent.

49. The apparatus of claim 44, wherein the first optical device comprises one or more lenses.

50. The apparatus of claim 44, wherein the first optical device is wavelength dependent.

51. The apparatus of claim 44, wherein the first optical device is dynamically adjustable.

52. The apparatus of claim 44, wherein the light emitted from the emitters is diverging such that a portion of the light emitted from the emitters forms an intersection, and the first optical device is placed at approximately the intersection.

53. The apparatus of claim 44, wherein the light emitted from the emitters is diverging such that a portion of the light emitted from the emitters forms an intersection, and the first optical device is placed before the intersection.

54. The apparatus of claim 44, wherein the light emitted from the emitters is diverging such that a portion of the light emitted from the emitters forms an intersection, and the first optical device is placed after the intersection.

55. The apparatus of claim 44, wherein the first optical device collimates the light.

56. The apparatus of claim 44, wherein the second optical device comprises at least one reflecting surface.

57. The apparatus of claim 44, wherein the second optical device comprises a plurality of reflecting surfaces.

58. The apparatus of claim 56, wherein the reflecting surface comprises a wavelength-dependent coating.

59. The apparatus of claim 44, wherein the third optical device comprises a lens.

60. The apparatus of claim 44, wherein the third optical device collimates the light.

61. The apparatus of claim 44, wherein the third optical device focuses the light.

62. An apparatus for reducing etendue of a system, the system having a plurality of light emitters separated by gaps, said apparatus comprising:

an optical system for reducing gaps between beams of light emitted from the emitters.

63. The apparatus of claim 62, wherein the optical system reduces a solid angle of the emitters.

64. The apparatus of claim 62, wherein the optical system comprises a first optical device for collimating light.

65. The apparatus of claim 64, wherein the optical system comprises a second optical device, the second optical device having at least one reflective surface.

66. The apparatus of claim 65, wherein the optical system comprises a third optical device for focusing light.