Micromirror spatial light modulator

• US 4,698,602 A
• Filed: 10/09/1985
• Issued: 10/06/1987
• Est. Priority Date: 10/09/1985
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Armitage, David
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Hellner, Mark
• Application Number:
  US06/785,691
• Time in Patent Office: 727 Days
• Field of Search: 350/342, 350/356, 350/386, 350/392, 350/360, 332/7.51
• US Class Current: 359/294
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field

Abstract

A micromirror spatial light modulator having an associated silicon photodiode for photoaddressing a micromirror array, and a readout system for providing intensity-to-position encoding and for providing a color image from coded monochromatic input light.

Claims

1. A micromirror spatial light modulator comprising

a micromirror array formed on a substrate and having a two dimensional configuration of electrostatically deflectable micromirror elements;

a silicon photodiode having a charge retaining grid formed on a surface thereof;

means for positioning said micromirror array within ten microns from said charge retaining grid;

means for applying a voltage between said photodiode and said micromirror array;

a metallic screen grid positioned between said silicon photodiode and said micromirror array and electrically isolated from said surface of said silicon photodiode by a layer of silicon dioxide; and

means for selectively applying a voltage to said metallic screen grid.

2. A micromirror spatial light modulator as defined in claim 1 wherein said micromirror array is positioned five microns from said charge retaining grid and wherein said layer of silicon dioxide has a thickness of 0.2 microns.

3. A micromirror spatial light modulator as defined in claim 1 and further comprising:

a Schlieren optical system coupled to the output of said spatial light modulator including a Fourier plane mask and providing intensity to position encoding.

4. A micromirror spatial light modulator as defined in claim 3 wherein said Fourier plane mask comprises contiguous red, green and blue filter strips whereby the intensity of coded monochromatic light applied to said spatial light modulator is modulated to provide a color image.