Abstract

Consider a three-level system 1, 2, and 3 with the transition between the first two driven by a pump laser, while the latter two are coupled by a Stokes laser (see Fig. 1). Level 2 decays by spontaneous emission also to levels other than levels 1 and 3. We confirm experimentally previous suggestions^1,2 that the counterintuitive sequence of interactions with the Stokes laser preceding the pump laser leads to the formation of a new type of trapped state, provided there is a suitable overlap in time.

© 1990 Optical Society of America