Recent Photon Echo Experiments

Vitali V. Samartsev

Valéria Loureiro da Silva, Yaron R. Silberberg

Recently we reported the first photon echo experiments in Er-doped fibers, and described their application to ultrafast time domain signal processing [1]. Our previous results were obtained with absorbing Er-doped fibers at 4°K, and our signals at 1.53µm were attenuated by the fiber. In this paper we report photon echo experiments with Er-doped amplifiers. We expect the photon echo process in amplifiers to yield strong echoes, perhaps stronger then the input signal. This could be important for signal processing applications. To our knowledge this is the first demonstration of photon echo in any inverted system.

Mark F. Arend

Raymond John Beach, Burton Brody, Sven R. Hartmann

Photon Echoes in gases are analyzed via the Billiard Ball Echo Model both in the short and long pulse limit where the “atoms” are represented as spherical and elliptical billiard balls, respectively. Recent experiments demonstrating the elliptical billiard ball shape are presented using intensity data which ranges over close to eleven orders of magnitude.

James L. Skinner, Hans C. Andersen, M. D. Fayer

We present the theory of the photon echo and stimulated photon echo from a four level system that results from a pair of weakly coupled two level systems. This model describes an impurity dimer in a molecular crystal. We include the effect of relaxation processes, focusing on energy transfer between delocalized states. We find that both the photon and stimulated echoes contain information about static level splittings and dynamic energy transfer processes. Moreover, these observables show a dramatic dependence on the excitation power. We discuss implications of our results for recent experiments on concentration dependent dephasing of impurities in molecular crystals. Our analysis casts considerable doubt on the intermolecular interaction interpretation of these experiments.

Махвиладзе Тариэль Михайлович, Сарычев Михаил Евгеньевич