US 5,859,728 AGranted

Method and apparatus for improved spatial light modulation

AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration

InventorsSoutar Colin, Richard D. Juday

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

A method and apparatus for modulating a light beam in an optical processing system is described. Preferably, an electrically-controlled polarizer unit and/or an analyzer unit are utilized in combination with a spatial light modulator and a controller. Preferably, the spatial light modulator comprises a pixelated birefringent medium such as a liquid crystal video display. The combination of the electrically controlled polarizer unit and analyzer unit make it simple and fast to reconfigure the modulation described by the Jones matrix of the spatial light modulator. A particular optical processing objective is provided to the controller. The controller performs calculations and supplies control signals to the polarizer unit, the analyzer unit, and the spatial light modulator in order to obtain the optical processing objective.

Claims40

Dependent claims

A method in an optical processing system of processing a light beam, comprising the method steps of:

(a) providing at least one of the following optical processing devices:
(i) an electrically-actuable polarizer unit which polarizes an incident light beam in a selected one of a plurality of available polarization states in response to receipt of at least a selected one of a plurality of available electrical command signals;
and
(ii) an electrically-actuable analyzer unit which selects from an incident light beam one of a plurality of available polarization states in response to receipt of at least a selected one of a plurality of available electrical command signals;
and
(b) providing the following optical processing devices;
(i) a spatial light modulator for receiving an incident light beam and modulating said incident light beam by converting one polarization state into another in accordance with an optical polarazation transform associated with an operating range of at least one drive parameter;
and
(ii) a controller member for supplying control signals to at least one of (a) said electrically-actuable polarizer unit, and (b) said electrically-actuable analyzer unit, and for supplying at least one drive parameter value to said spatial light modulator;
(c) passing said light beam through said spatial light modulator, and at least one of said electrically-actuable polarizer unit and said electrically-actuable analyzer unit;
(d) providing a particular optical processing objective to said controller member;
(e) utilizing said controller member to supply control signals to at least one of said electrically-actuable polarizer unit and said electrically-actuable analyzer unit, and to supply at least one drive parameter value to said spatial light modulator to obtain said optical processing objective without mechanical rotation of either of said electrically-actuable polarizer unit and said electrically-actuable analyzer unit.

9 more elements

An optical processing apparatus for modulating a light beam, comprising:

a polarizer unit which polarizes said light beam in a selected one of a plurality of available polarization states in response to receipt of at least a selected one of a plurality of available electrical command signals;
and
a spatial light modulator for receiving said light beam and modulating said light beam by converting one polarization state into another in accordance with an optical polarization transform associated with an operating range of at least one drive parameter;
and
an analyzer unit which selects from said light beam one of a plurality of available polarization states in response to receipt of at least a selected one of a plurality of available electrical command signals;
and
a controller member for supplying control signals to at least one of (a) said polarizer unit, and (b) said analyzer unit, and for supplying at least one drive parameter value to said spatial light modulator;
wherein, during a modulation mode of operation:
said controller member is utilized to supply control signals to at least one of said polarizer unit and said analyzer unit, and to supply at least one drive parameter value to said spatial light modulator to obtain said optical processing objective without mechanical rotation of either of said electrically-actuable polarizer unit and said electrically-actuable analyzer unit.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/327,762Filed 24 Oct 1994
Granted: 12 Jan 1999
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

G02B 27/46
Diffraction optics , i.e. systems including a diffractive element being designed for providing a diffractive effect: systems using spatial filters
G06E 3/005
Analogue devices in which mathematical operations are carried out with the aid of optical or electro-optical elements: using electro-optical or…
G06V 10/88
Arrangements for image or video recognition or understanding: image or video recognition using optical means, e.g. reference filters, holographic…
G02B
Optical elements, systems or apparatus