Holographic recording medium with control of photopolymerization and dark reactions

Abstract

The present invention relates to a system, as well as articles and holographic recording medium comprising the system, where the system comprises: a polymerizable component comprising at least one photoactive polymerizable material; and a photoinitiator component comprising at least one photoinitiator for causing the polymerizable component to polymerize to thereby form a plurality of holographic gratings when activated by exposure to a photoinitiating light source; wherein when a portion of the polymerizable component has been polymerized to form at least one holographic grating, the unpolymerized portion of the polymerizable component is resistant to further polymerization when not exposed to the photoinitiating light source. The present invention also provides methods for forming at least one holographic grating in a holographic recording medium having such a photopolymerizable system.

1 .- 190 . (canceled) 
     
     
         191 . A composition comprising a support matrix and a polymerizable system in the support matrix, the polymerizable system comprising:
 a polymerizable component comprising at least one photoactive polymerizable material; and   a photoinitiator component comprising at least one photoinitiator for causing the polymerizable component to polymerize to thereby form at least one holographic grating in a given volume of the holographic recording medium when activated by exposure to a photoinitiating light source;   wherein when a portion of the polymerizable component has been polymerized to form at least one holographic grating in the given volume, further polymerization of the unpolymerized portion of the polymerizable component in the given volume: (1) is deliberately controlled and substantially retarded to minimize dark reactions when not exposed to the photoinitiating light source; and (2) can occur when further exposed to the photoinitiating light source;   wherein the polymerizable system further comprises one or more polymerization retarders so that further polymerization of the unpolymerized portion of the polymerizable component is deliberately controlled and substantially retarded to minimize dark reactions when not exposed to the photoinitiating light source; and   wherein the one or more of the polymerization retarders or inhibitors are attached to the support matrix.   
     
     
         192 . The composition of  claim 191 , wherein the one or more of the said polymerization retarders comprise 2-(1,2-ethyldiol)-nitrobenzene.