Fabrication of Cr4+,Nd3+: YAG transparent ceramics for self-Q-switched laser

摘要

Transparent 0.1 at.%Cr, 1.0 at.%Nd:YAG (Y3Al5O12) ceramics were fabricated by a solid-state reaction and vacuum sintering with CaO as a charge compensator and tetraethyl orthosilicate (TEOS) as a sintering aid using high-purity powders of Al2O3, Y2O3, Nd2O3 and Cr2O3. The mixed powder compacts were sintered at 1800 degrees C for 5 h and 30 h under vacuum. The optical transmittance of the Cr,Nd:YAG ceramics sintered at 1800 C for 5 h and 30 h is similar to 63% and similar to 78% in the infrared wavelengths, respectively. The two samples exhibit pore-free structures and the average grain size is about 10 and 20 mu m. For the sample sintered at 1800 degrees C for 5 h, the dominant fracture mechanism is the transgranular fracture. With increase of holding time up to 30 h the ratio of intergranular fracture surfaces increase and more Cr3+ ions in the Cr,Nd:YAG ceramic transform to Cr4+. High-quality Cr4+,Nd3+:YAG transparent ceramics may be a potential self-Q-switched laser material. (c) 2006 Elsevier B.V. All rights reserved.