Growth, optical properties, and CW laser action of neodymium-doped gadolinium scandium aluminum garnet

Investigation of the congruent melting rare-earth aluminum garnet Gd
3
Sc
2
Al
3
O
12
(GADSCAG) has been made. The optimum crystal growth parameters for the undoped material are a rotation rate of 20 r/min and a growth rate of 4.6 mm/hr along the
\langle111\rangle
direction. For Nd
³⁺
-doped crystals the linear growth rate is 2 mm/h. The optical properties of Nd:GADSCAG which are of interest for laser operation were also determined. The stimulated emission cross section of the 1.06-μ transition in Nd
³⁺
at room temperature is
(3.2 \pm 0.3) \times 10^{-19}
cm
²
, the fluorescence lifetime is
256 \pm 8 \mu
s at an Nd
³⁺
ion density of 1 atomic percent in the crystal and the integrated peak absorption cross section in the strongest pump band (0.81 μ) is
3.8 \times 10^{-19}
cm
²
, A comparison of the CW laser performance of identical ND:YAG and Nd:GADSCAG rods is presented.