Complex spatial light modulator

• US 7,227,687 B1
• Filed: 06/22/2005
• Issued: 06/05/2007
• Est. Priority Date: 06/25/2004
• Status: Active Grant

• Current Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Original Assignee: Silicon Light Machines Corporation (SCREEN Holdings Co., Ltd.)
• Inventors: Carlisle, Clinton B., Payne, Alexander P., Trisnadi, Jahja I.
• Primary Examiner(s): Mack; Ricky
• Assistant Examiner(s): Dinh; Jack
• Application Number:
  US11/165,399
• Time in Patent Office: 713 Days
• Field of Search: 359/237, 359/238, 359/276, 359/278, 359/279, 359/559, 359290-293, 359/298
• US Class Current: 359/559
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

One embodiment relates to a spatial light modulator (SLM) for modulating light incident thereon. The SLM includes a plurality of pixels, each pixel including a plurality of phase shift elements. The SLM also includes a transform filter adapted to control the imaging system to resolve each pixel but not each phase shift element in each pixel. The plurality of pixels are controlled to independently modulate phase and magnitude of light reflected therefrom. Other embodiments are also disclosed.

Claims

1. A spatial light modulator (SLM) for modulating light incident thereon, the spatial light modulator comprising:

a plurality of pixels, each pixel including a plurality of phase shift elements; and

a Fourier transform filter adapted to control the imaging system to resolve light reflected from each pixel but not light reflected from each phase shift element in each pixel,

wherein the plurality of pixels are controlled to independently modulate phase and magnitude of light reflected therefrom.

2. The SLM according to claim 1, wherein the plurality of phase shift elements are configured such that substantially all light reflected from the SLM comes from the phase shift elements.

3. The SLM according to claim 1, further comprising:

a substrate having an upper surface, wherein the plurality of phase shift elements are disposed above the upper surface of the substrate,

a plurality of electrostatically displaceable mirrors, where each phase shift element comprises at least one said mirror; and

circuitry for applying voltages causing electrostatic forces between the substrate and the plurality of electrostatically displaceable mirrors to deflect each electrostatically displaceable mirror relative to the upper surface of the substrate.

4. The SLM according to claim 3, wherein the circuitry is configured to independently control the deflection of each electrostatically displaceable mirror.

5. The SLM according to claim 4, wherein two or more of the electrostatically displaceable mirrors are electrically connected together.

6. The SLM according to claim 3, wherein the circuitry for applying the voltages to cause the electrostatic forces is controlled so that each of the plurality of electrostatic mirrors are deflectable in an analog range of distances.

7. The SLM according to claim 6, wherein the circuitry for applying the voltages to cause the electrostatic forces is controlled so that a gray scale is achieved in the magnitude of the light reflected by the pixels.

8. The SLM according to claim 3, wherein each of the plurality of electrostatically displaceable mirrors comprise a movable actuator disposed above the upper surface of the substrate, the movable actuator having affixed thereto at least one of said mirrors to reflect light incident on the SLM.

9. The SLM according to claim 8, wherein the movable actuator is flexibly supported above the upper surface of the substrate by a plurality of posts extending from the upper surface of the substrate and by a plurality of flexures extending from a peripheral edge of the movable actuator to at least one of the plurality of posts.

10. The SLM according to claim 9, wherein each of the electrostatically displaceable mirrors further comprise:

a support affixed to the top surface of the actuators;

a mirror surface supported by the support above the actuators, flexures and posts; and

wherein peripheral edges of the mirror surface abuts peripheral edges of adjoining mirror surfaces such that substantially none of the light incident on the SLM passes between the mirror surfaces to impinge on the actuators, flexures or posts.