Epsilon-near-zero medium for optical switches in Ho solid-state laser at 2.06 μm

Indium tin oxide (ITO), an epsilon-near-zero material in the low-dimensional family, was successfully fabricated and first used as an optical switcher in 2.06 mu m. In the Tm:fiber pumped passively Q-switched laser, a maximum average output power of 312 mW was obtained with a shortest pulse width of 2.42 mu s and a repetition rate of 20.53 kHz, corresponding to a single pulse energy and a peak power of 15.20 mu J and 6.28 W, respectively. Results suggest that ITO is looking forward to develop into a kind of suitable saturable absorber for generation of nanosecond pulse in solid state lasers.