Generation and relaxation of photon echoes

Ming Tian, Zeb W. Barber, Tiejun Chang +2 more

Thomas M. Baer

Photon echoes generated from visible transitions in the noble gases helium, neon, and argon are observed and the collisional relaxation rates are measured. The photon echoes are excited on transitions initiating from metastable states which are populated by electron impact in an rf discharge. The photon-echo intensity is measured as a function of time after the discharge is turned off and as a function of gas pressure. The reduction of the echo intensity in these two experiments is attributed to relaxation of the metastable population in the afterglow and dephasing collisions, respectively. The dependence of the photon-echo damping time on transition wavelength and perturber gas is interpreted by means of a simple van der Waals model for the excited-atom and perturber-gas interaction.

Carrie S. Cornish

Tong Wang, Christoph M. Greiner, Jason R. Bochinski +1 more

We have studied the effect of generative-pulse amplitude, spatial profile, and temporal character as well as medium optical thickness on the power of photon and stimulated echoes. Working in atomic Yb vapor, photon echoes are observed that, absent material relaxation, are more powerful than the first generative pulse, thereby exceeding typically expected photon-echo powers by approximately two orders of magnitude. Factors crucial to the generation of powerful echoes identified through Maxwell-Bloch simulation are experimentally confirmed.

M. R. Woodworth

Photon-echo relaxation rates are measured in weakly ionized plasmas of binary mixtures of noble gases, in which the photon echo generated on a transition in one noble-gas species is damped primarily by atoms of the second species. The special cases of pure krypton and xenon are extensions of previous work in pure helium, neon, and argon. With the exception of mixtures with helium as the perturber, measured relaxation rates are consistent with collisional line-broadening calculations.

A.I. Alekseyev, Ashat M. Basharov, Igor V. Yevseyev