Optical electronic device with partial reflector layer

• US 20060018348A1
• Filed: 09/29/2005
• Published: 01/26/2006
• Est. Priority Date: 04/30/2003
• Status: Active Grant

• Current Assignee: Arthur R. Piehl, James R. Przybyla
• Original Assignee: Arthur R. Piehl, James R. Przybyla
• Inventors: Przybyla, James R., Piehl, Arthur R.
• Granted Patent: US 7,218,438 B2
• Time in Patent Office: Days
• US Class Current: 372/20
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: H01S 3/105 by controlling the mutual position or the reflecting properties of the reflectors of the cavity , e.g. by controlling the cavity lengthH01S3/10076, H01S3/13 take precedence

Abstract

An optical electronic device with a partial reflector layer is disclosed. The device includes a first reflector and a second reflector that define an optical cavity therebetween. The first and second reflectors are tuned to be selective of a visible wavelength at an intensity by optical interference. The second reflector includes at least one material having a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum. A mechanism is included which is configured to permit variation of the optical cavity.

Claims

1. An optical electronic device with a partial reflector layer, the optical electronic device comprising:

a first reflector and a second reflector defining an optical cavity therebetween, the second reflector including at least one material having a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum; and

a mechanism configured to permit variation of the optical cavity.

2. The optical electronic device as defined in claim 1 wherein the first and second reflectors each have a first face and an opposed second face, wherein the second face of the second reflector is positioned towards the first face of the first reflector, and the spatial light modulator further comprises at least one insulating layer disposed on at least one of the first face of the first reflector and the second face of the second reflector.

3. The optical electronic device as defined in claim 2 wherein the at least one insulating layer includes at least one of silicon dioxide, silicon nitride, silicon carbide, or mixtures thereof.

4. The optical electronic device as defined in claim 1 wherein the first reflector has a reflectivity of at least 90%.

5. The optical electronic device as defined in claim 4 wherein the first reflector includes at least one of aluminum, aluminum copper, aluminum alloys, silicon, silver, gold, platinum, tantalum, nickel, or mixtures thereof.

6. The optical electronic device as defined in claim 1 wherein the second reflector includes at least one layer of titanium, tantalum aluminum, titanium nitride, tungsten silicon nitride, alloys thereof, or mixtures thereof.

7. The optical electronic device as defined in claim 1, further comprising a layer of a material disposed on a first face of the second reflector, the layer of material adapted to provide sufficient rigidity to the second reflector such that the layer of material acts as a stiffening layer.

8. The optical electronic device as defined in claim 7 wherein the stiffening layer has an extinction coefficient (k) ranging between about 0 and about 0.005 across the visible spectrum.

9. The optical electronic device as defined in claim 8 wherein the stiffening layer includes at least one of silicon dioxide, silicon nitride, silicon carbide, or mixtures thereof.

10. The optical electronic device as defined in claim 7, further comprising at least one anti-reflective layer disposed on the stiffening layer and opposed the first face of the second reflector.

11. The optical electronic device as defined in claim 10 wherein the at least one anti-reflective layer includes magnesium difluoride.

12. The optical electronic device as defined in claim 1 wherein the mechanism allows a thickness of the optical cavity to be varied to select at least one of the visible wavelength and the intensity.

13. The optical electronic device as defined in claim 1 wherein the mechanism includes a flexure operatively connected to one of the first and second reflectors.

14. The optical electronic device as defined in claim 1 wherein a thickness of the second reflector is less than about 200 angstroms.

15. A method of making an optical electronic device with a partial reflector layer, the method comprising the steps of:

establishing a first reflector on a substrate;

positioning a second reflector in spaced relationship to the first reflector, thereby defining an optical cavity therebetween, the second reflector comprising at least one material having at least one of a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum; and

establishing a flexure layer between the first and second reflectors such that the flexure layer is operatively connected to one of the first reflector and the second reflector.

16. The method as defined in claim 15, further comprising establishing a circuit capable of introducing a charge sufficient to vary at least one optical property of the optical cavity by controlling a predetermined amount of charge stored on the first and second reflectors, such that at least one of visible wavelength and intensity are variably selectable to correspond with a pixel of a displayable image.

17. The method as defined in claim 15 wherein the first and second reflectors each have a first face and opposed second face, wherein the second face of the second reflector is positioned towards the first face of the first reflector, and the method further comprises establishing at least one insulating layer on at least one of the first face of the first reflector and the second face of the second reflector, wherein the at least one insulating layer is configured to prevent electrical shorting between the first and second reflectors.

18. The method as defined in claim 15, further comprising establishing a layer of a material on a first face of the second reflector, the layer of material adapted to provide sufficient rigidity to the second reflector such that the layer of material acts as a stiffening layer.

19. The method as defined in claim 18, further comprising establishing at least one anti-reflective layer on the stiffening layer and opposed the first face of the second reflector.

20. The method as defined in claim 15 wherein the second reflector includes at least one layer of titanium, tantalum aluminum, titanium nitride, tungsten silicon nitride, alloys thereof, or mixtures thereof.

21. An integrated circuit for at least partially displaying a pixel of a displayable image, comprising:

a semiconductor substrate;

a first reflector disposed on the semiconductor substrate;

a second reflector positioned a spaced distance from the first reflector, the first and second reflectors defining an optical cavity therebetween, wherein the first and second reflectors are tunable to be selective of a visible wavelength at an intensity by optical interference, the second reflector including at least one material having a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum; and

a charge controlling mechanism adapted to permit variation of the optical cavity.

22. The integrated circuit as defined in claim 21 wherein the second reflector includes at least one layer of tantalum aluminum, titanium nitride, tungsten silicon nitride, or mixtures thereof.

23. The integrated circuit as defined in claim 21 wherein each of the first and second reflectors have a first face and opposed second face, wherein the first face of the first reflector positioned towards the second face of the second reflector, and the integrated circuit further comprising at least one insulating layer disposed on at least one of the first face of the first reflector and the second face of the second reflector.

24. The integrated circuit as defined in claim 23 wherein the at least one insulating layer includes silicon dioxide, silicon nitride, silicon carbide, or mixtures thereof, and wherein the at least one insulating layer is configured to prevent electrical shorting between the first and second reflectors.

25. The integrated circuit as defined in claim 21, further comprising a layer of a material disposed on a first face of the second reflector, the layer of material providing sufficient rigidity to the second reflector such that the layer acts as a stiffening layer, wherein the stiffening layer has an extinction coefficient (k) ranging between about 0 and about 0.005 across the visible spectrum

26. The integrated circuit as defined in claim 25, further comprising at least one anti-reflective layer disposed on the stiffening layer and opposed the first face of the second reflector.

27. The integrated circuit as defined in claim 25 wherein the stiffening layer includes at least one of silicon dioxide, silicon nitride, silicon carbide, or mixtures thereof.

28. The integrated circuit as defined in claim 26 wherein the at least one anti-reflective layer includes magnesium difluoride.

29. The integrated circuit as defined in claim 21 wherein a thickness of the second reflector is less than about 200 angstroms.

30. A display device having a light path, the display device comprising:

a light modulation device on the light path for selectively reflecting a portion of the beam of light along a second light path in response to image data signals; and

a controller for providing image data signals to the light modulation device;

wherein the light modulation device comprises;

a first reflector and a second reflector defining an optical cavity therebetween, wherein the first and second reflectors are tuned to be selective of a visible wavelength at an intensity by optical interference, the second reflector comprising at least one material having a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum; and

a charge controlling mechanism configured to permit variation of the optical cavity.

31. The display device as defined in claim 30 wherein the second reflector includes at least one layer of titanium, tantalum aluminum, titanium nitride, tungsten silicon nitride, alloys thereof, or mixtures thereof.

32. The display device as defined in claim 30, further comprising a layer of a material disposed on a first face of the second reflector, the layer of material adapted to provide sufficient rigidity to the second reflector such that the layer of material acts as a stiffening layer.

33. The display device as defined in claim 32, further comprising at least one anti-reflective layer disposed on the stiffening layer and opposed the first face of the second reflector.

34. The display device as defined in claim 30 wherein a thickness of the second reflector is less than about 200 angstroms.

35. A projector comprising the display device of claim 30.

36. An optical electronic device, comprising:

means for substantially fully reflecting light; and

means for partially reflecting light, the partially reflecting light means including at least one material having a refractive index and an extinction coefficient, each ranging between about 1 and about 5 across the visible spectrum.

37. The optical electronic device as defined in claim 36, further comprising stiffening means for supporting the partially reflecting means.

38. The optical electronic device as defined in claim 36, further comprising means for minimizing reflection of the device.

39. The optical electronic device as defined in claim 36, further comprising means for insulating the device.