Enhancement of the laser emission efficiency of Yb:Y2O3 ceramics via multi-step sintering method fabrication

Abstract Highly transparent 5.0 at.% Yb:Y2O3 ceramics were successfully fabricated by using an optimal content of La2O3 and ZrO2 sintering additives and multi-step sintering method. The sintering process of the ceramics was based on a combination of two-step sintering in air followed by vacuum sintering. In-line optical transmission reached 78.5% at 1100 nm and 80% at 2000 nm. The absorption cross-section at 978 nm and the stimulated emission cross-section at 1032 nm were determined to be 2.23 × 10−20 cm2 and 1.42 × 10−20 cm2, respectively. Laser emission at 1.03 μm with a high slope efficiency of 33% was obtained from a 1.5 mm thick Yb:Y2O3 uncoated ceramic medium under quasi-continuous wave pumping at 971 nm with a fiber-coupled diode laser.