Abstract

We present a matter-wave analogue to an acousto-optic light modulator: an optical Bragg-modulator for atomic de Broglie waves. In our case an atomic beam is diffracted at a traveling light crystal formed by retroreflection of phase- or intensity-modulated light waves at a plane mirror. The modulation produces frequency sidebands separated from their carrier frequency by the modulation frequency. After retroreflection a superposition of different frequency contributions creates slowly traveling "subgratings". The diffraction angle at such slowly traveling gratings changes by δθ_b=v_g/v_a with respect to the stationary case (v_G and v_A are the velocities of the propagating light crystal and the atomic beam).

© 1996 IEEE