E2→T22Absorption Spectrum of Ruby

Abstract

Four of the six possible components in the sharp-line absorption spectrum ${}_{}{}^2{}_{}{}^{}E\left({t_2}^3\right)\to {}_{}{}^2{}_{}{}^{}T_2^{}{}_{}{}^{}\left({t_2}^3\right)$ have been observed in a sample of 0.05% ruby cooled to 95°K. The measured wavelengths and linewidths of the transitions are identical, within experimental error, to those calculated on the basis of observed absorptions to each of the excited levels from the ${}_{}{}^4{}_{}{}^{}A_2^{}{}_{}{}^{}$ ground state. The polarizations and relative strengths of the transitions are in good agreement with the existing crystal-field-theory predictions of Tanabe and Sugano.