Interaction strength of weakly coupled pairs measured by a two laser spectroscopy technique

Abstract

When the coupling between two ions associated in pair exceeds a given value, the excitation of both ions of the pair is impossible when using a single narrow laser. This double excitation was obtained with two lasers of different wavelengths. A narrowing of the inhomogeneous broadened lines is observed which gives information on the strain field in the crystal. From the difference between the wavelengths, the order of magnitude of the coupling is deduced and compared with phonon assisted transfer rates