Two dimensional electro-optic modulator for optical processing

• US 4,557,563 A
• Filed: 08/17/1984
• Issued: 12/10/1985
• Est. Priority Date: 10/08/1981
• Status: Expired due to Fees

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sprague, Robert A.
• Primary Examiner(s): ARNOLD, BRUCE
• Application Number:
  US06/641,803
• Time in Patent Office: 480 Days
• Field of Search: 350/162.12, 350/162.13, 350/162.14, 350/356, 340/783
• US Class Current: 359/315
• CPC Class Codes: G02F 1/0316 Electrodes
• CPC Class Codes: G02F 1/315 based on the use of controlled internal reflection
• CPC Class Codes: H04N 1/036 for optical reproduction
• CPC Class Codes: H04N 1/19505 Scanning picture elements spaced apart from one another in at least one direction
• CPC Class Codes: H04N 1/19515 in two directions
• CPC Class Codes: H04N 1/19531 Reflecting elements
• CPC Class Codes: H04N 1/19547 Apertures
• CPC Class Codes: H04N 1/19573 Displacing the scanned image

Abstract

A two dimensional electro-optic modulator comprises an electro-optic element and a two dimensional planar array of individually addressable electrodes for spatially modulating a light beam along a plurality of transverse axes or for imparting a geometric phase front to the light beam. Such a modulator may be used, for example, (1) in a real time or in a time delay and integration mode as a multigate light valve for (a) electro-optic line printing or (b) optical displays, or (2) in a real time mode as (a) a beam focusing and tracking device for optical memories or (b) an areal input device, a Fourier plane filter, or an image plane correlation mask for optical processing.

Claims

1. An electro-optic device for optical data processing, said device comprising

an electro-optic element having a reflective surface;

a two dimensional planar array of individually addressable electrodes proximate the reflective surface of said electro-optic element;

means for applying a light beam to said electro-optic element at a near grazing angle of incidence with respect to said reflective surface for total internal reflection therefrom, said light beam illuminating said reflective surface over an area which is substantially coextensive with said array;

means for applying data to said electrodes, whereby fringe electric fields are coupled into said electro-optic element to spatially modulate said light beam essentially simultaneously in two dimensions in accordance with said data; and

a focusing lens optically aligned with said electro-optic element for bringing said modulated light beam to focus, thereby providing an optical Fourier transform of said data.

2. The electro-optic device of claim 1 wherein

said electrodes are supported independently of said electro-optic element but closely adjacent the reflective surface thereof, whereby said electric fields are proximity coupled into said electro-optic element in response to said data.

3. The electro-optic device of claim 1 further including

read out means optically aligned with said electro-optic element for imparting an intensity profile to said light beam corresponding to the spatial modulation thereof for image plane optical processing, said read out means including said focusing lens.