BeAl6O10:Cr3+ (Ti3+, Ni2+) laser crystals and their spectroscopic characteristics

Abstract The EPR, optical absorption, luminescence spectra, and lasing characteristics of Cr 3+ , Ti 3+ , and Ni 2+ ions in BeAl 6 O 10 (beryllium hexaaluminate, BHA) crystals are studied. The spectroscopic data show that the BHA crystals have an orthorhombic structure with the space group Pbcm. The temperature dependence of luminescence lifetime of the excited state of Cr 3+ ions ( τ ≈13×10 −6 s at 300 K) is investigated. The energy gap between the 2 E- and 4 T 2 -levels of Cr 3+ (∼236 cm −1 ) and the nonradiative relaxation activation energy ( E a ≈1667 cm −1 ) are determined. High-efficient tunable radiation of a new BeAl 6 O 10 :Cr 3+ laser crystal is demonstrated in the region of 0.78–0.92 μm at 300 K. It is shown that the doped BHA crystals are promising active media for tunable solid state lasers in the spectral regions of 0.7–1.0 μm (Cr 3+ ) and 1.35–1.65 μm (Ni 2+ ).