  Many optical systems use acousto-optics for fast steering of light. However,
acousto-optic (AO) light diffraction permits manipulation and shaping of light
fields in a much broader sense including holography. While acousto-optic
devices operate at incontestable speed, they are one dimensional (1D)
diffraction devices depending on analog serial data transfer and as such have a
mode of use distinguished from common 2D spatial light modulators. Combination
with an amplified laser source allows to clock the serial buildup of AO
diffraction patterns for avoidance of phase aberration in the output beam due
to acoustic wave progression. Pseudo 2D holography is established with two
crossed AO deflectors for biaxial spatial modulation of the input phase, and
optionally also of its amplitude. In this configuration, acousto-optics permits
light patterning into micrometer-scale 2D point grids with the possibility to
switch the pattern between individual laser pulses. We describe algorithms for
deriving AO holograms for either pure phase modulation or for a co-modulation
of amplitude. Computationally reconstructed phase holograms show focal patterns
in presence of side lobes. Side lobes are entirely suppressed by amplitude
modulation, though at the expense of reduced optical power transmission.
