WS2 as a saturable absorber for Q-switched 2 micron lasers.

ABSTRACT

We prepared WS2 nanosheets by using the thermal decomposition method and demonstrated for the first time its nonlinear saturable absorption property at around 2 µm. With the as-prepared WS2 nanosheets as saturable absorber (SA), a passively Q-switched TmLuAG laser was realized successfully, and 660 ns laser pulses with an average output power of 1.08 W and pulse peak power of 26 W at a repetition rate of 63 kHz were obtained for an incident pump power of 7 W. Our experimental results definitely demonstrate that WS2 could be a kind of promising SA for solid-state 2 µm lasers.