The optical properties and laser characteristics of Cr3+ and Nd3+ co-doped Y3Al5O12 ceramics

We have fabricated Cr3+ and Nd3+ co-doped YAG (Cr;Nd:YAG) ceramics, and investigated their optical properties and laser characteristics. The Cr;Nd:YAG has two broad absorption bands at around 440 nm (4A2→4T1) and 600 nm (4A2→4T2) respectively, caused by Cr3+ ions. In the case of pumping at 440 nm, the maximum effective lifetime of the Cr;Nd:YAG was 737 μs with a 0.1 at% Cr3+ and 1.0 at% Nd3+ co-doped YAG sample. Cr3+ ions take a role of an effective sensitizer to convert the UV light of flashlamp. For single-shot laser operation, a 10.4 J output energy at 1064 nm was obtained with 0.1 at% Cr3+ and 1.0 at% Nd3+ co-doped YAG ceramic rod with a laser efficiency of 4.9%. The laser efficiency was found to be more than twice that of a 1.0 at % Nd3+:YAG ceramic rod.