Influence of inversion creation processes in atomic transitions on four - wave parametric oscillation process (FWPOP) under optical pumping of barium and europium vapor

摘要

Processes of inversion creation in a number of barium and europium atomic transitions under pumping of vapors by eximer XeCl~* and KrF~* lasers have been investigated. Qualitative study of inversion creation mechanisms that are common for barium and europium atoms has been carried out. Necessary conditions for observation of atom lines of Ba and Eu amplified spontaneous emission (ASE) have been formulated. It has been found that observed absence of longwave satellites of Eu resonant lines is caused by ASE absence in atomic transitions 8p~8P_(9/2) → 6d~8D~0_(7/2) and 8p~8P_(9/2) → 6d~8D~0_(11/2) of europium atom. Whereas, absence of ASE in transitions 8p~8P_(9/2) → 6d~8D~0_(7/2) and 8p~8P_(9/2) → 6d~8D~0_(11/2) of Eu atom is a result of high offset, or starting of pre-dissociating pumping channel of 6d~8D~0_(7/2,11/2) Eu levels. Problems, caused by of undetermined nature of resonant emission that is observed under optical pumping of europium and barium vapor, are discussed in this paper.