Patent ID: 7092134

Claim:
Method of forming a hologram from a information containing mask, comprising the following steps: arranging a substrate bearing a layer of a holographic recording medium on a first face of a coupling element and in optical contact therewith; arranging a information containing mask in a spaced relationship and parallel to the substrate; generating an illumination light beam and then splitting the light beam into an object beam and a reference beam; directing the reference beam to a second face of the coupling element in a way that the condition for total internal reflection at the interface between the recording medium and the ambient medium is fulfilled directing the object beam through the mask to the substrate such that it overlaps with the reference beam in the holographic recording medium; employing a photoresist as the holographic recording medium; and arranging the planes of polarisation of the object and reference beams incident on the holographic recording medium such that their polarisation vectors are substantially mutually orthogonal in the holographic recording medium and such that the polarisation vectors of the incident and totally internally reflected reference beams are also substantially orthogonal; and the step of employing a photoresist includes employing a photoresist whose layer thickness is less than 500 nm.