Photon-echo decay due to weak velocity-changing collisions

Ravinder Kachru, THOMAS W. MOSSBERG, Sven R. Hartmann

THOMAS W. MOSSBERG, Ravinder Kachru, Edward A. Whittaker +1 more

Ruwang Sung, P. R. Berman

The effect of velocity-changing collisions in an extended-pulse photon echo is studied. In an extended-pulse photon echo, the second excitation pulse has a duration comparable with the relaxation time of an atomic system. We present an analytic solution of the quantum-mechanical transport equation in the perturbation-theory limit and apply it to the extended-pulse photon echo. It is found that the decay rate of the echo signal due to velocity-changing collisions is significantly modified by the variation of the second pulse's duration. The results are compared with those of conventional theories of two- and three-pulse echoes using temporally narrow excitation pulses. A physical interpretation of the results is given using both time- and frequency-domain arguments.

L.A. Gel'Medova, David A. Shapiro

The extra photon echo decay due to ion-ion, velocity-changing collisions is computed. The strong velocity dependence of the collision frequency is shown to decrease the decay constant by 30%.

I. V. Evseev, Решетов Владимир Александрович

Norman A. Kurnit, Sven R. Hartmann