Tilt multiplex holography

Process for shift holography in which an array of holograms is recorded in a recording medium defining the x-y plane, the array consisting of holograms each produced by interference of a reference beam and a signal beam together defining a plane of incidence, and each consisting of a multiplicity of holographic grating vectors having a predominant grating vector direction in the x-y plane, the array consisting of successive rows of partially overlapping holograms produced by movement of the recording medium relative to the beams in the shift direction, thereby defining the x-direction, with successive rows produced by movement in the direction orthogonal to the shift direction, thereby defining the y-direction, whereby partially overlapping holograms may be individually read out using Bragg selection,

• CHARACTERIZED IN THAT
• the line of interception of the plane of incidence and the x-y plane is non-coincident with the shift direction, and diverges by a divergence angle as measured in the x-y plane, whereby a grating vector component is introduced into the y-direction, thereby permitting first-order Bragg selectivity in the y-direction and serving for selection of partially overlapping holograms in the y-direction.