COLLISIONAL DECAY AND REVIVAL OF THE GRATING STIMULATED ECHO

A theory is presented that describes collision-induced modifications of the grating stimulated echo (GSE) signal. In the GSE [B. Dubetsky, P. R. Berman, and T. Sleator, Phys. Rev. A 46, 2213 (1992)], a spatially modulated atomic population is created which undergoes Doppler dephasing and rephasing as a result of the interaction of the atoms with a number of input pulses. At low pressures, there is a rapid decay of the GSE signal owing to a collisional breaking of the dephasing-rephasing process. At high perturber pressures, however, there can be a revival of the GSE signal owing to a collisional inhibition of the Doppler dephasing. These collisional processes are described in detail, with a special emphasis given to the distinction between ''open'' and ''closed'' atom-field systems. The manner in which the GSE can be used to determine collision kernels and diffusion coefficients is also discussed.