Methods of Recording and Reproducing Holograms

A method comprising:

• a) recording a hologram in a thresholded opto-magnetic medium, including
• a(i) producing a collimated recording beam with a pulsed laser,
• a(ii) selectively modulating intensity of the recording beam by passage through a modulator to produce a modulated recording beam,
• a(iii) spatially shaping the modulated recording beam by passage through a shaping element to produce a shaped modulated recording beam,
• a(iv) causing the shaped modulated recording beam to be convergent by passage through an aspheric lens to produce a convergent shaped modulated recording beam,
• a(v) deflecting bidirectionally with a MEMS mirror that is in operative connection with the modulator, the convergent shaped modulated recording beam, wherein multiple disposed locations on a surface of the opto-magnetic medium are exposed to a constriction of the convergent shaped modulated recording beam,
• wherein the constriction of the convergent shaped modulated recording beam at the surface
• has an asymmetrical cross section, and
• causes a change in magnetization of magnetic domains of the medium where the energy of the constriction exceeds a threshold of magnetization reaction of the magnetic domains,
• b) subsequent to recording the hologram, reconstructing the hologram including:
• b(i) illuminating the changed opto-magnetic medium of (a)(v) with a collimated laser beam,
• b(ii) focusing with a lens, light from the illuminated opto-magnetic medium onto a detection matrix.