PROGRAMMABLE DIFFRACTION GRATING

• US 3,861,784 A
• Filed: 06/29/1973
• Issued: 01/21/1975
• Est. Priority Date: 06/29/1973
• Status: Expired due to Term

• Current Assignee: Ernest J. Torok
• Original Assignee: Ernest J. Torok
• Inventors: Torok, Ernest J.
• Primary Examiner(s): Stern, Ronald J.
• Assistant Examiner(s): Godwin, Paul K.
• Application Number:
  US05/375,255
• Time in Patent Office: 571 Days
• Field of Search: 350/151,162R,161
• US Class Current: 359/573
• CPC Class Codes: G02F 1/091 based on magneto-absorption or magneto-reflection
• CPC Class Codes: G03H 1/2294 Addressing the hologram to an active spatial light modulator

Abstract

An electrically alterable apparatus and method of operation thereof that permits the optical processing of an image is disclosed. The apparatus includes an array of optical cells comprised of a plurality of XY stripline arrays and a stripedomain film element. The stripe-domain wall separation and wall orientation at each point in the film element are selectively controllable for generating in the optical cell array an electrically alterable hologram. Domain wall configurations to perform various optical processing tasks are disclosed.

Claims

1. A programmable diffraction grating, comprising:

a planar matrix array of X directional magnetic field generating elements;

a planar matrix array of Y directional magnetic field generating Y elements;

pairs of interacting ones of each of said X and Y elements arranged in an interacting X and Y directioned magnetic field configuration;

X current source selection means selectively coupled to each of said X elements for selectively coupling an X selection current of selectable polarity and amplitude to a selected one of said X elements;

Y current source selection means separately coupled to each of said Y elements for selectively coupling a Y selection current of selectable polarity and amplitude to a selected one of said Y elements;

a plurality of coplanar stripe-domain film elements, a separate one inductively coupled to only a separate pair of said interacting X and Y elements for forming XY optical cells;

current control means concurrently controlling said X and Y current source selection means for concurrently coupling selected X and Y selection currents of selected polarities and amplitudes to a selected one of said pairs of said interacting X and Y elements for generating in the plane of the one inductively coupled stripe-domain film element a resultant DC magnetic field HR of a predetermined direction and magnitude;

AC field means inductiveLy coupled to said XY optical cells and coacting with the associated resultant DC magnetic fields HR for generating a selected configuration of substantially continuously different dimensioned stripe-domain wall separations in said plurality of coplanar stripe-domain film elements.

2. The grating of claim 1 in which said AC magnetic field is directed substantially normal to the plane of said film elements.

3. The grating of claim 1 in which said film elements are individual portions of a continuous layer.

4. A programmable diffraction grating, comprising:

an array of optical cells, each optical cell including;

a planar stripe-domain film element;

orthogonal X and Y directioned-magnetic-field-generating X and Y elements inductively coupled to said film element;

means for inductively coupling an AC magnetic field to said array of optical cells;

selection means coupled to said X and Y elements for generating in the plane of each of said film elements a resultant DC magnetic field of a predetermined orientation and magnitude;

control means controlling said selection means for separately determining the particular orientation and magnitude of each of said resultant DC magnetic fields in the plane of each of said film elements;

a fixed configuration of stripe domains established in said film elements of said array of optical cells by said resultant DC magnetic fields in which interdomain walls are substantially continuous across two or more adjacent ones of said fillm elements, said interdomain walls having different dimensioned wall separations.

5. The grating of claim 4 in which said AC magnetic field is directed substantially normal to the planes of said film elements.

6. The grating of claim 4 in which said AC magnetic field is of a sufficient magnitude to overcome the hysteresis of said film elements during the initial application of said resultant DC magnetic fields.

7. The grating of claim 4 in which said AC magnetic fields are directed substantially normal to said interdomain walls.

8. The grating of claim 4 in which said film elements of said array of optical cells are individual portions of a continuous layer.

9. The grating of claim 4 in which said wall separations differ between adjacent interdomain walls and along adjacent interdomain walls.

10. The grating of claim 4 in which said fixed configuration of stripe domains is comprised of a series of interdomain walls forming concentric circles of successively decreasing dimensioned wall separations.

11. The grating of claim 4 in which said fixed configuration of stripe domains is comprised of a series of interdomain walls forming parallel straight lines of successively decreasing dimensioned wall separations.