Spontaneous Emission from a four level Λ-V system

Xiangming Hu, Qing Yang Xu, Jing-yan Li +3 more

Francesco Plastina, Franco Piperno

Xiangqian Jiang, Xiudong Sun

P. L. Knight

Nadeem A. Ansari

Quantum mechanical theory of a non-degenerate correlated emission laser in a four-level atomic system in the double-Λ configuration is presented. It is shown that the mode coupling gains in this model have a phase-sensitive nature so that the spontaneous emission events in the two modes are highly correlated in such a way that the relative phase diffusion coefficient can vanish under certain conditions. Also, because of mode coupling and for a certain range of atomic population in the upper atomic levels, lasing without inversion and correlated emission take place simultaneously. Stability conditions and the steady-state modal ratio are derived and it is shown that this ratio remains stable and for this stationary value of the modal ratio both the modes amplify with equal gains.

Fei Song, Jinyu Chen, Zhiping Wang +1 more

We investigate high-precision three-dimensional (3D) atom localization in a coherently-driven, fourlevel atomic system via spontaneous emission. Space-dependent atom-field interactions allow atomic position information to be obtained by measuring spontaneous emission. By properly varying system parameters, atoms within a certain range can be localized with nearly a probability of 100% and a maximal resolution of ~ 0.04λ. This scheme may be useful for the high-precision measurement of the center-of-mass wave functions of moving atoms and in atom nanolithography.