Holographic data storage system having thermoplastic substrates

Abstract

In one embodiment, holographic data storage medium includes a first thermoplastic substrate portion having a thickness less than approximately 2 millimeters and a second thermoplastic substrate portion having a thickness less than approximately 2 millimeters. A holographic recording material may be sandwiched between the first and second thermoplastic substrate portions. By making thermoplastic substrate portions sufficiently thin, edge wedge problems can be avoided.

1 . A holographic data storage system comprising: 
 a laser that produces at least one laser beam;    optical elements through which the laser beam passes;    a data encoder that encodes data in at least part of the laser beam;    a holographic recording medium that stores at least one hologram, the holographic recording medium comprising: 
 a first thermoplastic substrate portion having a thickness less than approximately 1.2 millimeters,  
 a second thermoplastic substrate portion having a thickness less than approximately 1.2 millimeters, and  
 a holographic recording material between the first and second  
   thermoplastic substrate portions; and    a data detector that detects the hologram.    
     
     
         2 . The holographic data storage system of  claim 1 , wherein the data encoder comprises a spatial light modulator.  
     
     
         3 . The holographic data storage system of  claim 1 , wherein the data detector comprises a camera.  
     
     
         4 . The holographic data storage system of  claim 1 , wherein the first and second thermoplastic substrate portions are made of at least one of the following: polycarbonate, polymethylmethacrylate, and amorphous polyolefin.  
     
     
         5 . The holographic data storage system of  claim 1 , wherein the holographic recording material is a photopolymer.  
     
     
         6 . The holographic data storage system of  claim 1 , wherein the medium is a disk.  
     
     
         7 . The holographic data storage system of  claim 1 , wherein the first and second thermoplastic substrate portions have thicknesses less than approximately 1.2 millimeters.  
     
     
         8 . The holographic data storage system of  claim 1 , wherein the first and second thermoplastic substrate portions have thicknesses equal to approximately 1.2 millimeters.  
     
     
         9 . The holographic data storage system of  claim 7 , wherein the first and second thermoplastic substrate portions have thicknesses less than approximately 0.6 millimeters.  
     
     
         10 . The holographic data storage system of  claim 7 , wherein the first and second thermoplastic substrate portions have thicknesses equal to approximately 1.2 millimeters.  
     
     
         11 . The holographic data storage system of  claim 1 , wherein the first and second thermoplastic substrate portions are injection molded substrate portions.  
     
     
         12 . The holographic data storage system of  claim 1 , wherein the holographic recording material has a thickness of approximately 1 millimeter.  
     
     
         13 . The holographic data storage system of  claim 1 , wherein the first and second thermoplastic substrate portions have a thickness less than 1.3 millimeters and greater than 0.5 millimeters.  
     
     
         14 . A method comprising: 
 injection molding a first substrate portion and a second substrate portion;    depositing a photopolymer between the first and second substrate portions;    forcing the first substrate portion onto an upper reference plane;    forcing the second substrate portion onto a lower reference plane; and    curing the photopolymer.    
     
     
         15 . The method of  claim 14 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses less than approximately 2.0 millimeters.  
     
     
         16 . The method of  claim 15 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses less than approximately 1.2 millimeters.  
     
     
         17 . The method of  claim 15 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses equal to approximately 1.2 millimeters.  
     
     
         18 . The method of  claim 16 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses less than approximately 0.6 millimeters.  
     
     
         19 . The method of  claim 16 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses equal to approximately 0.6 millimeters.  
     
     
         20 . The method of  claim 15 , wherein injection molding the first substrate portion and the second substrate portion comprise injection molding the first and second substrate portions to have first and second substrate thicknesses less than 1.3 millimeters and greater than 0.5 millimeters.  
     
     
         21 . The method of  claim 14  wherein depositing a photopolymer between the first and second substrate portions comprises injecting the photopolymer between the first and second substrates by center dispensing the photopolymer through an inner diameter of at least one of the substrate portions.