Concentration dependence of the Ebar-]2abar far-infrared transition of excited chromium ions in ruby

Abstract

The absorption due to electronic transitions between the excited Image (2E) state and the 2Image (2E) state of Cr3+ ions in optically pumped ruby is studied by Zeeman spectroscopy with a far-infrared laser. We find that the linewidth and the oscillator strength of the Image → 2Image transition increase quadratically with the chromium concentration for ruby crystals containing more than 0.1 wt.% Cr2O3.