Discrete element light modulating microstructure devices

Abstract

A light modulating or switching array ( 10 ) having a plurality of discrete protrusions ( 16 ) formed of electro-optic material, each of which is electrically and optically isolated from each other. The protrusions ( 16 ) have defined a top face ( 20 ), a bottom face ( 30 ), first and second side faces ( 22, 24 ), and front and back faces ( 26, 28 ). There are a plurality of electrodes ( 34 ) associated with each of the protrusions ( 16 ), these electrodes ( 34 ) being capable of inducing an electric field in the electro-optic material for independently modulating a plurality of light beams which are incident upon one of the faces ( 20, 22, 24, 26, 28, 30 ) of the protrusions ( 16 ). The electro-optic material may be of PLZT, or a member of any of the groups of electro-optic crystals, polycrystalline electro-optic ceramics, electro-optic semiconductors, electro-optic glasses and electro-optically active polymers. Also disclosed is a light modulating array ( 10 ) of the type having a matrix ( 136 ) of electro-optic material which contains a plurality of embedded adjacent electrodes ( 134 ). These electrodes ( 134 ) are capable of inducing an electric field in the electro-optic material for independently modulating a plurality of light beams which are incident upon the matrix ( 136 ) of electro-optic material. This matrix ( 136 ) can be formed by a variety of processes, including a sol-gel process. Additionally disclosed is a system ( 11 ) in which light modulating arrays ( 10 ) are used to modulate incident light beams ( 42 ) and separate them into a plurality of data channels ( 94, 96 ).

What is claimed is:  
     
         1 . A light modulating array comprising: 
 a plurality of discrete protrusions formed of electro-optic material, each discrete protrusion being electrically and optically isolated from each other, said protrusions further having defined a top face, a bottom face, first and second side faces, and front and back faces; and    a plurality of electrodes associated with each of said protrusions, said electrodes being capable of inducing an electric field in said electro-optic material for independently modulating one or more light beams which are incident upon one of said faces of said protrusions.    
     
     
         2 . The light modulating array of  claim 1  wherein: 
 said protrusions are formed from a single wafer of electro-optic material and said bottom faces of said protrusions are integral with said wafer.  
 
     
     
         3 . The light modulating array of  claim 1  wherein: 
 said protrusions are formed on a separate substrate layer.  
 
     
     
         4 . The light modulating array of  claim 1  wherein: 
 said protrusions are separated by regions of dielectric material.  
 
     
     
         5 . The light modulating array of  claim 1  wherein: 
 each of said first side faces are angled such that incident light beams are internally reflected within said protrusions.  
 
     
     
         6 . The light modulating array of  claim 5  wherein: 
 said second side face is angled such that incident light beams are directed to exit said protrusions.  
 
     
     
         7 . The light modulating array of  claim 6  wherein: 
 said first and second angled faces include a reflective means.  
 
     
     
         8 . The light modulating array of  claim 1  wherein: 
 said electro-optic material is selected from the group consisting of electro-optic crystals, polycrystalline electro-optic ceramics, electro-optically active polymers, electro-optic semiconductors and electro-optic glasses.  
 
     
     
         9 . The light modulating array of  claim 8  wherein: 
 said electro-optic material is PLZT where the lanthanum concentration lies in the range of 8.5% to 9.0% of the overall composition.  
 
     
     
         10 . The light modulating array of  claim 1  wherein: 
 said electrodes are attached to said first and second side faces of said protrusions.  
 
     
     
         11 . The light modulating array of  claim 1  wherein: 
 said electrodes are attached to said front and rear faces of said protrusions and said electrodes include an aperture for passage of light beams.  
 
     
     
         12 . The light modulating array of  claim 2  wherein: 
 said wafer includes a bottom surface; and  
 an electrode is attached to each top face of each of said protrusions and one or more electrodes contact said bottom surface of said wafer.  
 
     
     
         13 . The light modulating array of  claim 3  wherein: 
 an electrode is attached to each said top face of each said protrusion and said substrate layer includes one or more electrodes which contact said bottom face of each of the protrusions in the array.  
 
     
     
         14 . The light modulating array of  claim 1  wherein: 
 each of said protrusions includes a first portion of said electro-optic material to which a plurality of electrodes is associated, and each of said protrusions further includes a second portion composed of material with an index of refraction matching that of said first portion when no voltage is applied to electro-optically activate said first portion, but said index of refraction of said second portion is less than the index of refraction of said first portion when said first portion is electro-optically activated by application of appropriate voltage;  
 said first and second portions are in close conjunction with each other such that a boundary is formed at the junction of said first and second portions; and  
 each of said protrusions is oriented with respect to one or more light beams such that said each of the light beams enters each first portion of each protrusion and strikes said boundary between said first and said second portions at an angle such that each light beam is totally reflected internally when said first portion is electro-optically activated by application of sufficient voltage, but which will pass unreflected through said boundary when said first portion is not electro-optically activated.  
 
     
     
         15 . A light modulating array comprising: 
 a plurality of discrete protrusions formed of electro-optic material, each discrete protrusion being electrically and optically isolated from each other, said protrusions further being formed in a prism shape having defined a top face, a bottom face, and front and rear faces;    a plurality of electrodes associated with each of said protrusions, said electrodes being capable of inducing an electric field in said electro-optic material for independently modulating one or more incident light beams; and    each of said prism shaped protrusions is oriented with respect to one or more light beams such that each light beam incident upon said front face of said protrusion enters each protrusion traveling a first path and emerging at a first angle from said rear face of said protrusion when no voltage is applied to electro-optically activate said protrusion, but each light beam travels a second path and emerges at a second angle from said rear face of said protrusion when said protrusion is electro-optically activated by application of appropriate voltage.    
     
     
         16 . A light modulating array comprising: 
 a matrix of electro-optic material; and    said matrix containing a plurality of embedded adjacent electrodes, said electrodes being capable of inducing an electric field in said electro-optic material for independently modulating one or more light beams which are incident upon said matrix of electro-optic material.    
     
     
         17 . A light modulating array as in  claim 16  wherein: 
 said electrodes are embedded in said matrix material by a process selected from the group consisting of sol-gel deposition, molding, etching of the matrix followed by electrode placement, and micro-machining of the matrix.  
 
     
     
         18 . A system for modulating light comprising: 
 one or more discrete protrusions formed of electro-optic material, each discrete protrusion being electrically and optically isolated from each other, said protrusions having defined a top face, a bottom face, one or more side faces, and front and back faces;    a plurality of electrodes associated with each of said protrusions, said electrodes being capable of inducing an electric field in said electro-optic material for independently modulating one or more light beams incident upon one of said faces of said protrusions, the light beams being linearly polarized in a first polarization orientation;    a power supply capable of supplying sufficient voltage to induce a desired polarization shift from a first polarization orientation to a second polarization orientation in a beam of polarized light entering said protrusions;    conductive means for conducting electricity from said power supply to said plurality of electrodes;    switching means for controlling application of voltage to said electrodes through said conducting means; and    separation means for separating light of a first polarization orientation from light of a second polarization orientation.    
     
     
         19 . The system for modulating light of  claim 18  wherein: 
 said conductive means includes conductive pads which are connected to said electrodes in a configuration to be selected from the group consisting of two conductive pads on the top surface of each protrusion, a conductive pad on each side surface of each protrusion, and a conductive pad on the top surface of each protrusion and a conductive pad on each of one or more electrodes which are associated with the bottom of each protrusion,  
 
     
     
         20 . The system for modulating light of  claim 18  wherein: 
 said separation means is an output polarizer having a polarization orientation, said polarizer being positioned to transmit linearly polarized light output from said protrusions having the same polarization orientation as that of said output polarizer.  
 
     
     
         21 . The system for modulating light of  claim 18  wherein: 
 said separation means is a beam splitter, said beam splitter being positioned so that light of a first polarization orientation is passed through said beam splitter, and light of a second polarization orientation is reflected.