Fabrication and laser behaviors of Nd:YAG ceramic microchips

Transparent Nd:YAG ceramic microchips were fabricated through the slip casting shaping directly from the slurry formed by the commercial Al2O3/Y2O3/Nd2O3 powders, and followed by the vacuum sintering procedure. Viscosity of the slurries, the phase evolution and the densification behavior were investigated. For the Al2O3/Y2O3/Nd2O3 compound slurries system, the optimal condition is 0.5 wt.% NH4PAA dispersant and 30 wt.% solid loading at pH ≥ 8. The YAG phase started to form at 1250° C and pure YAG phase could be obtained at 1400° C. The optical in-line transmittance of the Nd:YAG ceramics with thickness of 2 mm was about 83.8% at 1064 nm and 82.5% at 400 nm, which hit the upper limit of the theoretically calculated value. For the 1.0 at.% Nd:YAG ceramic microchip, the slope efficiency was 43% for 1.0 at.% Nd:YAG ceramic pumped by 920 mW cw Ti:sapphire tunable laser, and the maximum laser output power 246 W was obtained for 2.0 at.% Nd:YAG ceramics pumped by 925 W LD.