High-Power Passively Q-Switched Nd:YVO₄ Laser Based on WS₂ Saturable Absorber

In this paper, we fabricated a novel tungsten disulfide (WS₂) saturable absorber (SA) using sol-gel technology and successfully applied it into a Q-switched solid-state laser for the first time. By using sol-gel technology, WS₂ materials are completely separated into sol-gel silica glass, which can effectively protect the WS₂ materials from oxidation and other damages. Inserting the WS₂ SA into the Nd:YVO₄ laser cavity and adjusting it, a stable Q-switched pulse was obtained. The average output power was 3.09 W, the repetition rate was 3.38 MHz and the corresponding pulse duration was 99 ns. As far as we know, this is the highest average output power of WS₂ SA used in Nd-doped solid state lasers, and the pulse duration is also quite narrow. It shows that sol-gel technology has great potential to make practical two dimensional material absorbers.