Diode-pumped laser oscillation in highly Nd3+-doped polycrystalline Y3Al5O1
2 (YAG) ceramics has been demonstrated. The Nd:YAG ceramics are highly tran
sparent; the loss of a 2.3 at. % neodymium-doped ceramic is as low as that
of a 0.9 at. % Nd:YAG single crystal. The high doping of Nd3+ ions realizes
large pump absorption; a 6.6 at. %-doped ceramic has an absorption coeffic
ient of 60.4 cm(-1) at 808 nm. The same concentration quenching parameter i
s obtained between the Nd:YAG ceramics and Nd:YAG single crystals. A laser
using an 847-mu m-thick 3.4 at. % Nd:YAG ceramic as a gain medium operates
at 2.3 times higher output power than the same laser with a 719-mu m-thick
0.9 at. % Nd:YAG single-crystal gain medium. (C) 2000 American Institute of
Physics. [S0003-6951(00)03233-2].