Method and device for modulating light with optical compensation

• US 8,422,108 B2
• Filed: 12/18/2009
• Issued: 04/16/2013
• Est. Priority Date: 11/06/1995
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Primary Examiner(s): Lester, Evelyn A.
• Application Number:
  US12/642,750
• Publication Number:
  US 20100214642A1
• Time in Patent Office: 1,215 Days
• Field of Search: 359/223, 359/224, 359290-292, 359/295, 359/298, 359/315, 359/318, 345/48, 345/84, 345/85, 345/90, 345/108, 348/750, 348/770, 348/771
• US Class Current: 359/224.1
• 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

Abstract

An interferometric modulator (Imod) cavity has a reflector and an induced absorber. A direct view reflective flat panel display may include an array of the modulators. Adjacent spacers of different thicknesses are fabricated on a substrate by a lift-off technique used to pattern the spacers which are deposited separately, each deposition providing a different thickness of spacer. Or a patterned photoresist may be used to allow for an etching process to selectively etch back the thickness of a spacer which was deposited in a single deposition. A full-color static graphical image may be formed of combined patterns of interferometric modulator cavities. Each cavity includes a reflector, and an induced absorber, the induced absorber including a spacer having a thickness that defines a color associated with the cavity.

Claims

1. A device, comprising:

a light-absorbing material including a semiconducting film;

a substrate located above said light-absorbing material;

a reflector located below said light-absorbing material; and

an optical resonant cavity, a portion of which is located between said light absorbing material and said reflector, wherein the cavity includes a dielectric film,

wherein a portion of light incident passing through the substrate is reflected by the reflector towards the light-absorbing material.

2. The device of claim 1, wherein the substrate includes one or more electrodes connected to a circuitry.

3. The device of claim 1, wherein the light-absorbing material further includes a metal film.

4. The device of claim 1, wherein the reflector is movable to alter the thickness of the optical resonant cavity and enable modulation of the light incident passing through the substrate.

5. The device of claim 1, wherein the reflector includes a metal film.

6. The device of claim 5, wherein the reflector includes a film of silver.

7. The device of claim 6, wherein the silver film is at least 50 nm thick.

8. The device of claim 1, wherein the light-absorbing material includes an absorber and one or more layers.

9. The device of claim 8, wherein the one or more layers includes a metal film.

10. The device of claim 8, wherein the one or more layers includes a dielectric film.

11. The device of claim 8, wherein the one or more layers includes the semiconductor film.

12. The device of claim 8, wherein the absorber includes the semiconducting film.

13. The device of claim 12, wherein the one or more layers includes a second semiconducting film.

14. The device of claim 1, wherein the device includes a part of a display array.