Calcium lithium niobium gallium garnet crystals activated with Er3+ and Cr3+ as a new active medium for 3-μ lasers

An investigation was made of the luminescence spectra and lasing properties of a calcium lithium niobium gallium garnet crystal activated with chromium and erbium. The lifetimes of the upper (⁴I_11/2) and lower (⁴I_13/2) active levels of the Er³⁺ ion were determined. A study was made of the kinetics of decay of the Cr³⁺ luminescence and it was concluded that energy was transferred from the Cr³⁺ to the Er³⁺ ions. Lasing properties of the crystal (λ_l = 2.707 μm) were studied under free-running conditions at room temperature.