Characteristics of Nd3+-doped Y3ScAl4O12 ceramic laser

Highly transparent Nd3+-doped Y3ScAl4O12 (YSAG) ceramics with up to 5.0 at.% Nd3+-concentration (CNd) were synthesized from commercial oxide powders with purity of >99.99% by a solid-state reaction method. Absorption, fluorescence, and decay properties of these materials were evaluated. Considering the influence of increasing CNd on these spectroscopic characteristics, it became clear that Nd:YSAG ceramics is suitable for the microchip laser or the mode-locked laser. We demonstrated microchip laser operation using highly concentrated Nd:YSAG. One-micron laser output power of 165 mW (37.0% optical-to-optical overall efficiency) and 49.5% slope efficiency were obtained under direct pumping into the emitting levels by a Ti:Sapphire laser from uncoated ceramic gain medium. Short-pulse generation from a passively mode-locked Nd3+-doped YSAG ceramic laser was also demonstrated, and this laser generated pulses of ∼10 ps with 560 mW average power (35% optical-to-optical efficiency) under cw mode-locking operation.