Reflective Langmuir–Blodgett Molybdenum Disulfide Saturable Absorber for Q-Switched Nd:GdVO₄ Laser

We fabricated a compact reflective molybdenum disulfide (MoS 2 ) saturable absorber (SA) by coating a few layers of a MoS 2 thin film on a silver mirror using the Langmuir-Blodgett (LB) method. The LB method showed to be effective in producing a thin film with smooth surface, low optical scattering, and low nonsaturable losses. By inserting the LB MoS 2 -SA into a V-shaped Nd:GdVO 4 laser cavity, a stable Q-switched laser operation with the maximum average output power of 0.89 W corresponding to a pulse width of 91.6 ns is obtained. The slope efficiency is as high as 44.4% and the optical conversion efficiency is 15.6%, indicating low losses of the LB MoS 2 -SA.