Abstract

Coupled ion pairs in solids have played an important role in the development of new solid-state lasers. The long-range interaction among two or more ions provides a channel for the inversion of population, leading to the discovery of new emission lines. Because of the relatively large optical cross sections, coupled ion pairs may provide new media for the implementation of a solid-state phase conjugate mirror. We present a theory of optical phase conjugation via four-wave mixing in such novel materials. For a model ion-doped solid-state system, the calculations give the following conclusions. First, the spectral linewidth is proportional to the square root of the intensity of the radiation field in an inhomogenously broadened material for fixed ion density. Second, the linewidth decreases with increasing ion density for the fixed intensity level. And last, the saturation intensity also decreases with increasing ion density for the fixed optical intensity. The behavior of the linewidth and the saturation intensity are attributed to the strong interaction among two nearest-neighbor ion pairs, which leads to the generation of additional energy dumping pathways.

© 1988 Optical Society of America