Abstract

For about 15 years, the atomic physics community has been aware of a phenomenon that is termed "population trapping.” When two lasers with frequencies that couple two lower states of an atom to a common upper state, or to a common continuum, are applied to an atom, the population is frozen or trapped in the lower states. The common upper state is empty, and the contribution of the atom to the steady-state linear susceptibility is zero.

© 1992 Optical Society of America