Homogeneously broadened far-infrared absorption line due to the Ebar-]2abar transition of excited chromium ions in ruby

Abstract

By use of far-infrared laser spectroscopy, we have found that for a high-quality ruby crystal at low temperature, the absorption line due to the electronic transition between the excited states Image and Image ions is previous termhomogeneouslynext term broadened. From the linewidth (0.011 cm-1) the lifetime of the 2Image level against emission of 29 cm-1 phonons is obtained.