Incandescent microcavity lightsource having filament spaced from reflector at node of wave emitted

• US 5,955,839 A
• Filed: 03/26/1997
• Issued: 09/21/1999
• Est. Priority Date: 03/26/1997
• Status: Expired due to Fees

• Current Assignee: Quantum Vision
• Original Assignee: Quantum Vision
• Inventors: Thayer, Jeffrey S., Jones, Michieal L., Jaffe, Steven M., Olmsted, Brian L., Eilers, Hergen
• Primary Examiner(s): Patel, Vip
• Assistant Examiner(s): Gerike, Matthew J.
• Application Number:
  US08/827,189
• Time in Patent Office: 909 Days
• Field of Search: 313/578, 313/620, 313/567, 313/522, 313/579, 313/580, 313/634, 313/27, 313/25, 313/37, 313/47, 313/112, 313/115, 313/636, 313/635
• US Class Current: 313/578
• CPC Class Codes: H01K 1/04 characterised by the material thereof
• CPC Class Codes: H01K 1/32 provided with coatings on the walls; Vessels or coatings thereon characterised by the material thereof
• CPC Class Codes: H01K 3/005 Methods for coating the surface of the envelope
• CPC Class Codes: H01K 3/02 Manufacture of incandescent bodies

Abstract

An incandescent microcavity lightsource 30 has an incandescent active region 13 capable of spontaneous light emission when heated. The incandescent microcavity lightsource 30 controls the spontaneous light emissions from said active region 13.

Claims

1. A device comprising:

an optical microcavity with an incandescent active region;

said incandescent active region having an incandescent light source disposed therein for emitting light;

said incandescent active region capable of having spontaneous light emission when heated; and

said optical microcavity including means for controlling the spontaneous light emission from said active region.

2. The device of claim 1, wherein the control of spontaneous light emission is achieved by the controlling means by decreasing the rate of certain emission.

3. The device of claim 1, wherein the control of spontaneous light emission is achieved by the controlling means by increasing the rate of certain emission.

4. The device of claim 1, wherein the control of spontaneous light emission is achieved by the controlling means by causing the reabsorption of energy.

5. The device of claim 1 wherein:

the controlling means include at least one mirror for controlling the spontaneous light emission from said active region.

6. The device of claim 1 wherein:

said controlling means include a lower mirror and an upper window/mirror; and

wherein said lower mirror reflects light back into said cavity, and said upper window/mirror reflects some light back into said cavity and allows some light to pass outwardly of said cavity.

7. The device of claim 1 including:

said incandescent active region includes an incandescent filament.

8. The device of claim 7 wherein:

said filament includes a polysilicon filament.

9. The device of claim 7 wherein:

said filament is selected from the group consisting of tungsten, tantalum, platinum, palladium, molybdenum, zirconium, titanium, nickel, and chromium or a carbide, nitride, boride, silicide, or oxide of these metals.

10. The device of claim 7 wherein:

said incandescent filament is comprised of a high temperature refractory material.

11. The device of claim 1 wherein:

the incandescent active region is capable of emitting wavelengths in at least one of an infrared range, a visible range, and an ultraviolet range.

12. The device of claim 1, wherein the control of spontaneous emission is achieved by the means for controlling by controlling the direction of such emission.

13. The device of claim 1, wherein the control of spontaneous emission is achieved by the means for controlling by controlling the wavelength of such emission.

14. The device of claim 1, wherein the control of spontaneous emission is achieved by the means for controlling by controlling emission polarizations.

15. The device of claim 1 wherein said optical microcavity is a multi-dimensional cavity.

16. A device comprising:

a resonant optical microcavity with an incandescent active region;

means for controlling spontaneous light emission from the incandescent active region; and

said active region having a source of incandescent light.

17. The device of claim 16 wherein:

said means for controlling can accomplish at least one of (1) increasing the rate of light emission;

(2) decreasing the rate of light emission; and

(3) causing reabsorption of energy by the incandescent lightsource in the active region.

18. The device of claim 16 wherein:

said means for controlling has at least one mirror that can control spontaneous light emission from said active region.

19. The device of claim 16 wherein:

said means for controlling include a lower mirror and an upper window/mirror; and

wherein said lower mirror reflects light back into said resonant optical microcavity, and said upper window/mirror reflects some light back into said resonant optical microcavity and allows some light to pass outwardly of said resonant optical microcavity.

20. The device of claim 16 wherein:

said incandescent lightsource can emit wavelengths in at least one of the infrared range, the visible range, and the ultraviolet range.

21. The device of claim 16 wherein:

said means for controlling can improve the efficiency of incandescent light emission through at least one of enhancement, suppression, and reabsorption of energy from the resonant optical microcavity.

22. The device of claim 16 wherein:

said incandescent active region includes an incandescent filament.

23. The device of claim 22 wherein:

said filament can be at least one of (1) suspended in said microcavity, and (2) form a boundary of said microcavity.

24. The device of claim 16 wherein:

said source of incandescent light is generated by an electrically heated filament.

25. The device of claim 16 wherein:

said controlling means includes a mirror which is positioned such that at least one of a node and an antinode of a standing wave are produced relative to the incandescent active region.

26. The device of claim 16 wherein:

said resonant optical microcavity is on of (1) evacuated or (2) filled with one or more gasses to create a controlled atmosphere.

27. The device of claim 16 wherein:

said means for controlling has a mirror which can pass some emission from said incandescent active region and which can reflect some emissions from said incandescent active region.

28. The device of claim 16 wherein:

said means for controlling includes a window which can pass emission from said incandescent active region.

29. A method of enhancing the output of a incandescent light source comprising the steps of:

providing an incandescent light source capable of having spontaneous light emission; and

providing means for controlling the spontaneous light emission from said incandescent light source in a resonant optical microcavity.

30. The method of claim 29 wherein said second providing step includes:

controlling the spontaneous light emission by at least one of (1) decreasing the rate of certain emissions, (2) increasing the rate of certain emissions, and (3) causing the reabsorption of energy.

31. An incandescent light source device comprising:

an optical microcavity with an incandescent active region;

said active region having an incandescent light source disposed therein for emitting light;

said incandescent active region has spontaneous light emission when heated; and

said optical microcavity controls the spontaneous light emission from said active region.

32. An incandescent light source device comprising:

an optical microcavity with an active region; and

said active region having an incandescent light source disposed therein for emitting light.

33. The incandescent light source device of claim 32 wherein said microcavity comprises:

a substrate;

a lower reflective region disposed upon said substrate;

said active region disposed upon said lower reflective region; and

an upper reflective region disposed upon said active region; and

at least one of said lower and said upper reflective regions is partially reflective, so that light produced by excitation of said active region forms a standing wave between said lower reflective region and said upper reflective region and is emitted through said at least one partially reflective region.

34. The incandescent light source device of claim 33 wherein said lower reflective region is a metallic reflector.

35. The incandescent light source device of claim 33 wherein said upper reflective region is a metallic reflector.

36. The incandescent light source device of claim 33 wherein said active region includes one of a doped polysilicon filament, a tungsten filament, and a tungsten alloy filament.

37. The incandescent light source device of claim 33, wherein said lower reflective region and upper reflective region are dielectric reflectors.

38. The incandescent light source device of claim 37 wherein said dielectric reflectors comprise a plurality of alternating parallel layers wherein a first layer of said layers comprises a material with a relatively low index of refraction and a second of said layers comprises a material with a relatively high index of refraction.

39. The incandescent light source device of claim 38 wherein said material with a relatively low index of refraction is selected from fluorides and oxides.

40. The incandescent light source device of claim 38 wherein said material with a relatively high index of refraction is selected from sulfides, selenides, nitrides and oxides.