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

In this paper, we fabricated a novel tungsten disulfide (WS
₂
) 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, WS
₂
materials are completely separated into sol-gel silica glass, which can effectively protect the WS
₂
materials from oxidation and other damages. Inserting the WS
₂
SA into the Nd:YVO
₄
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 WS
₂
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.