QUANTUM-THEORY OF THE MAZER .1. GENERAL-THEORY

The photon emission probability in a micromaser changes drastically wh en the kinetic energy of the pumping atoms is comparable to the atom-f ield interaction energy. In this situation, the atomic center-of-mass motion has to be treated quantum mechanically and the de Broglie wavel ength of the atom inside the cavity is an important physical parameter . The interplay between reflection and transmission of the atoms leads to a new mechanism for induced emission. A photon is emitted by an ex cited atom when the de Broglie wavelength fits resonantly into the cav ity. These resonances lead to the process of microwave amplification v ia z-motion-induced emission of radiation (mazer). We derive and illus trate a general expression for the emission probability and a master e quation for the mazer. We note that the probability for emission by an excited thermal atom (stimulated maser emission) is very different fr om the emission probability as given by the de Broglie resonances (ind uced mazer emission). [S1050-2947(97)01411-X].