We have theoretically predicted and experimentally demonstrated an ultra-dispersive atomic prism
made of coherently driven Rb atomic vapor. The prism posses spectral angular dispersion that six
orders of magnetude higher than the prism made from optical glass; it is the highest spectral angular
dispersion that has been ever shown (such angular dispersion allows one to resolve spatially light
separated by a few kHz). The prism is working near the resonant frequency of atomic vapor, and its
dispersion is optically controlled by coherent driving field.
We have experimentally demonstrated anomalous stimulated scattering of sound waves with optical waves of the same direction in a cell of Rb vapor. The optical wave is propagating under the conditions for ultra-slow group velocity. The phase-matching condition for the interaction of the waves is achieved when the group velocity of the probe field to approximately the speed of the sound wave.