Atomstrahlabbremsung mit der stimulierten bichromatischen Lichtkraft

This work reports the deceleration of a cesium atomic beam with the ''stimulated bichromatic force'' acting on two-level atoms in a superposition of two standing light waves of different frequency. The effective slowing of an atomic beam by a force exceeding the spontaneous force limit #Planck constant#k#gamma# could be demonstrated for the first time. Whthin a distance of only 10 cm the atoms were decelerated from 250 m/s down to 90 m/s by a force of nearly 10 #Planck constant#k#gamma#. In further experiments the final atomic velocity was reduced down to 8 m/s. The atomic flux of atoms through a 2 mm-diaphragm at a distance of 11 cm from the oven amounted to 1.10"9 atoms with velocities smaller than 50 m/s and 1.10"8 atoms with velocities smaller than 15 m/s. A further objective of the experiments was to quantitatively ivnestigate the stimulated bichromatic light force, which stands out among other light forces due to its strength combined with a broad velocity capture range with steep flanks. These properties, that are particularly interesting for many applications, were observed for the first time in the present work. In a series of systematic measurements we obtained atomic beam profiles which are in very good accordance with force profiles calculated under simplified conditions. In these measurements the force has proven to be relatively robust against a deviation from the ideal experimental parameters. After an intuitive explanation in a pulse train picture the force is described in the dressed atom model and the form of its remarkable velocity dependence is explained. We give a simple physical reason for its large width and show that it is due to a stimulated conversion of photons from one frequency component into the other. (orig.)SIGLEAvailable from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman