2.44Â KW laser output of Nd:YAG ceramic slab fabricated by a solid-state reactive sintering

The large-sized 1.0 at.% transparent Nd:YAG ceramic disk (Ø130 mm×6 mm) was fabricated by solid-state reactive sintering using a mixture of commerical Al2O3, Y2O3 and Nd2O3 powders. A fully dense Nd:YAG ceramic with an average grain size of ∼10 μm was obtained by vacuum sintering at 1750 °C for 50 h. The transmittance is 82.5% at the visible wavelength of 400 nm, which is very close to the theoretical value of single crystal with good optical quality. Under the same pumping condition, output powers of 2.44 and 2.51 KW are obtained corresponding to optical-to-optical efficiencies of 36.5% and 37.5% for Nd:YAG ceramic and single crystal slabs (93 mm × 30 mm × 3 mm), respectively. To the best of our knoledge, 2.44 KW is the highest output power for Nd:YAG ceramic fabricated by the solid-state reactive sintering method.