ATOM LASER-BASED ON RAMAN TRANSITIONS

In this paper we present an atom laser scheme using a Raman transition for the output coupling of atoms. A beam of thermal atoms (bosons) in a metastable atomic state is pumped into a multimode atomic cavity. T his cavity is coupled through spontaneous emission to another cavity f or the atomic ground state. Above a certain threshold pumping rate a l arge number of atoms build up in the lowest energy state of the second cavity, while the higher energy states remain unpopulated. Atoms are then coupled to the outside of the cavity with a Raman transition. Thi s changes the internal level of the atom and imparts a momentum kick, allowing the atoms to leave the system. We propose an implementation o f our scheme using hollow optical-fiber atom waveguides.