Disclosed is a holographic recording medium. The novel holographic recording mediums disclosed herein comprises: a) at least one polyfunctional epoxide monomer or oligomer which undergoes acid initiated cationic polymerization. Each epoxide in the monomer or oligomer is linked by group comprising a siloxane to a silicon atom and each monomer or oligomer has an epoxy equivalent weight of greater than about 300 grams/mole epoxide; b) a binder which is capable of supporting cationic polymerization; c) an acid generator capable of producing an acid upon exposure to actinic radiation; and optionally d) a sensitizer.