Two dimensional electro-optic modulator and applications therefor

• US 4,480,899 A
• Filed: 10/08/1981
• Issued: 11/06/1984
• 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:
  US06/309,650
• Time in Patent Office: 1,125 Days
• Field of Search: 350/356, 350/162.12, 350/162.13, 350/162.14, 350/162.15, 350/388, 358/230
• US Class Current: 359/263
• 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 modulator for spatially modulating a light beam essentially simultaneously in two dimensions in accordance with input voltages, said modulator comprising

an electro-optic element, and

a two dimensional planar array of individually addressable electrodes intimately associated with a reflective surface of said electro-optic element for coupling fringe electric fields into said electro-optic element in response to said input voltages, and

means for applying a light beam to said modulator at a grazing angle of incidence with respect to the reflective surface of said electro-optic element, said light beam illuminating said surface over an area which is essentially coextensive with said electrode array whereby said light beam is spatially modulated essentially simultaneously in two dimensions in accordance with said input voltages.

2. The electro-optical modulator of claim 1 wherein

said electrode array is a rectilinear array, whereby said light beam is spatially modulated essentially simultaneously along a pair of transverse axes in accordance with said input voltages.