A method of writing a spatially heterodyne hologram having spatially
heterodyne fringes includes: passing a single write beam through a
spatial light modulator that digitally modulates said single write beam;
and focusing the single write beam at a focal plane of a lens to impose a
holographic diffraction grating pattern on the photorefractive crystal,
the holographic diffraction grating pattern including the spatially
heterodyne hologram having spatially heterodyne fringes, wherein only
said single write beam is incident on said photorefractive crystal
without a reference beam. A method of replaying a spatially heterodyne
hologram having spatially heterodyne fringes at a replay angle includes:
illuminating a photorefractive crystal having a holographic diffraction
grating with a beam from a laser at an illumination angle, the
holographic diffraction grating pattern including the spatially
heterodyne hologram having spatially heterodyne fringes, wherein a
difference between said illumination angle and said replay angle defines
a diffraction angle .alpha. that is a function of a plane wave
mathematically added to original object wave phase and amplitude data of
said spatially heterodyne hologram having spatially heterodyne fringes.