Experiments are carried out on the spectroscopy of the Förster resonance lines Rb(37P) + Rb(37P) Rb(37S) + Rb(38S) and microwave transitions nP n'S, n'D between Rydberg states of cold rubidium atoms in a magnetooptical trap (MOT). Under ordinary conditions, all spectra exhibit a linewidth of 2–3 MHz irrespective of the interaction time between atoms or between atoms and microwave radiation, although the limit resonance width should be determined by the inverse interaction time. The analysis of exper imental conditions has shown that the main source of line broadening is the inhomogeneous electric field of cold photoions that are generated under the excitation of initial nP Rydberg states by broadband pulsed laser radia tion. The application of an additional electricfield pulse that rapidly extracts photoions produced by a laser pulse leads to a considerable narrowing of lines of microwave resonances and the Förster resonance. Various sources of line broadening in cold Rydberg atoms are analyzed.
Effect of Photoions on the Line Shape of the Förster Resonance Lines and Microwave Transitions in Cold Rubidium Rydberg Atoms
ARIMONDO, ENNIO
2012-01-01
Abstract
Experiments are carried out on the spectroscopy of the Förster resonance lines Rb(37P) + Rb(37P) Rb(37S) + Rb(38S) and microwave transitions nP n'S, n'D between Rydberg states of cold rubidium atoms in a magnetooptical trap (MOT). Under ordinary conditions, all spectra exhibit a linewidth of 2–3 MHz irrespective of the interaction time between atoms or between atoms and microwave radiation, although the limit resonance width should be determined by the inverse interaction time. The analysis of exper imental conditions has shown that the main source of line broadening is the inhomogeneous electric field of cold photoions that are generated under the excitation of initial nP Rydberg states by broadband pulsed laser radia tion. The application of an additional electricfield pulse that rapidly extracts photoions produced by a laser pulse leads to a considerable narrowing of lines of microwave resonances and the Förster resonance. Various sources of line broadening in cold Rydberg atoms are analyzed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
