We report on the near-infrared absorption, emission, and lifetime data of Cr4+:Lu3Al5O12 (Cr:LAG) and compare the results with the known laser material Cr4+-doped Y3Al5O12 (Cr:YAG). Lu3Al5O12 has a smaller unit cell than Y3Al5O12, and this feature is reflected in its spectroscopic properties. The low-temperature luminescence spectrum is shifted by 85 cm-1 to higher energy compared with Cr:YAG. The luminescence lifetime of Cr:LAG at 10 K is 28.7 µs (Cr:YAG, 30.6 µs) and at 300 K is 4.3 µs (Cr:YAG, 3.5 µs). From these lifetimes we postulate that the quantum efficiency in Cr:LAG is higher than in Cr:YAG. We discuss the potential of Cr:LAG as a tunable near-infrared laser.
© 1993 Optical Society of America
H. Eilers, U. Hömmerich, S. M. Jacobsen, W. M. Yen, and M. Kokta, "Spectroscopic properties of Cr4+:Lu3Al5O12," Opt. Lett. 18, 1928-1930 (1993)