High-efficiency diode-pumped Tm:LiGdF4 laser at 1.93 µm

Solid-state lasers emitting in the 2 µm spectral region find important applications in remote sensing and gas detection, in high-resolution molecular spectroscopy, in frequency metrology, in medicine and in optical communications. Thulium-doped crystals employed as active materials in lasers operating near 2 àm are attractive especially for their wide tunability and high efficiency [1], besides the advantage of direct diode pumping at 785 nm which allows the implementation of compact, reliable and rugged laser sources.