Abstract: An optically made, high-efficiency in-line holographic mask (ILHM) for in-line holographic patterning of a workpiece, and apparatus and methods for performing same. The ILHM combines the imaging function of a lens with the transmission properties of a standard amplitude mask, obviating the need for expensive projection optics. The ILHM is either a type I (non-opaque) or type II (opaque) specialized object mask having one or more substantially transparent elements which can be phase-altering, scattering, refracting and/or diffracting. A method of creating a pattern on a workpiece includes the steps of disposing an ILHM, disposing a workpiece adjacent the ILHM and illuminating the ILHM to impart a pattern to the workpiece. In another method, the ILHM is used in combination with a lens. The ILHM is disposed such that a holographic real image is formed at or near the lens object plane, and the workpiece is disposed at or near the lens image plane.

Abstract: The present invention is directed to a holographic media that is composed of a mixture of a photosensitive substance such as a photopolymer and a porous rigid material such as an aerogel that provides a substructure to the composite material. This unique composition of matter can be utilized in a multitude of applications where a thick optically patterned wavefront modulating media is required, including as a holographic storage device. The composite material avoids the difficulties regarding shrinkage found in plain photopolymers. The rigid highly porous component is specially treated to receive the photosensitive material. This unshrinkable substructure has a plurality of very small, rigid pores that is essentially transparent at optical wavelengths and provides the matrix for the photopolymers. It provides holographic recording in both thin and thick formats without shrinkage and pattern distortion. The method of producing the composite holographic media is also disclosed.