Eur. Phys. J. Plus (2014) 129: 254
https://doi.org/10.1140/epjp/i2014-14254-4

Regular Article

Laser power dependence of the Beutler-Fano profiles for the autoionizing Rydberg states of Ba

Department of Physics, Kuwait University, P.O. Box 5969, 13060, Safat, Kuwait

^* e-mail: kafrousheh@gmail.com

Received: 12 September 2014
Revised: 21 October 2014
Accepted: 24 October 2014
Published online: 26 November 2014

Abstract

The change of the Beutler-Fano profiles of the asymmetric autoionizing lines of barium as a function of the excitation laser power was investigated. Utilizing two-photon absorption, the J = 0 and 2 levels of a few members of the 5d_3/2 nd_3/2 autoionizing Rydberg series above the first ionization limit of barium were excited in a heat-pipe oven. As the laser power was changed, the transitions with relatively symmetric lineshapes showed the expected power broadening. However, the transitions with asymmetric lineshapes experienced a dramatic profile change while displaying a less significant power broadening. The remarkable profile changes are attributed to the interference between different ionization channels even at the highest excitation laser power.