Grazing incidence holograms and system and method for producing the same

A holographic recording process comprising:

• (a) supporting a recording medium upon a recording substrate so that an interface is established therebetween, said recording medium containing photopolymerizable monomers that are free to migrate within said recording medium in response to light exposure and the index of refraction of said recording medium n.sub.m being less than the refractive index of said recording substrate n.sub.s,
• (b) exposing said recording medium to a reference beam passing directly through said recording substrate at grazing incidence to the interface defined between said recording medium and said recording substrate, whereupon an evanescent wave is produced at said interface, causing said monomers in said polymerizable recording medium to migrate towards said interface, locally increasing the index of refraction adjacent said interface, and creating a gradient-type index matching region between said recording medium and said recording substrate;
• and
• (c) exposing said recording medium to an object beam from one side thereof, and simultaneously to a reference beam passing directly through said recording substrate at grazing incidence to the interface defined between said recording medium and said recording substrate, and allowing said reference beam to enter said recording medium and interact with said object beam to create a fringe pattern fixable within said recording medium.

A holographic recording system comprising:

• means for supporting a recording medium upon a recording substrate so that an interface is established therebetween, said recording medium containing photopolymerizable monomers that are free to migrate within said recording medium in response to light exposure and the index of refraction of said recording medium being less than the refractive index of said recording substrate,
• means for exposing said recording medium to a reference beam passing directly through said recording substrate at grazing incidence to the interface defined between said recording medium and said recording substrate, whereby an evanescent wave is produced at said interface, causing said monomers in said polymerizable recording medium to migrate towards said interface, thereby locally increasing the index of refraction adjacent said interface, and creating a gradient-type index matching region between said recording medium and said recording substrate;
• and
• means for exposing said recording medium to an object beam from one side thereof and simultaneously to a reference beam passing directly through said recording substrate at grazing incidence to the interface between said recording medium and said recording substrate, and allowing said reference beam to create a fringe pattern fixable within said recording medium.