Abstract

Heavily doped Er:YAG crystals are able to lase efficiently at 2.4 μm. Ion-ion interaction shown as cross-relaxation processes occur between several Er³⁺ levels and can affect both fluorescence decay and lasing properties.¹ We report observation of nonexponentlal fluorescence decay from the upper laser level of the Er³⁺ ions, the ⁴/_11/2 state. A rate equation model which Includes cross-relaxation is used to determine the strengths of various processes. It is shown that the crossrelaxation coefficients are independent of the Er³⁺ concentration. On the other hand, the cross-relaxation rate depends on the dopant ion density.

© 1988 Optical Society of America