Short pulse formation in a 2.3 µm Tm-doped tellurite glass laser by an Fe2+:ZnS saturable absorber

This letter demonstrates the passive Q-switching possibility of a 2.3 mu m Tm-doped tellurite glass laser with the help of a Fe2+:ZnS saturable absorber. In contrast to Cr2+-doped materials, this saturable absorber is transparent at the laser pump wavelengths (0.69 or 0.8 mu m). Pulses as short as 150-200 ns were formed.