  Dynamic cavity effect of a Topological Insulator Bi2Te3 based Passive
Q-switched (QS) solid state laser was investigated. With a saturation intensity
as low as a few kW, Bi2Te3 processed by hydrothermal exfoliation serves a
sensitive saturable absorber to initiate Q-switching. Without material damage,
a transition from QS state to CW state was observed when the pumping strength
increases which was explained by the modulation instability spectrum of laser
rate equation.
