Increased efficiency of Er:YAG lasers at 1645 nm using narrow bandwidth diode lasers and dual-wavelength resonant pumping

摘要

We demonstrate cw and Q-switched operation of Er:YAG laser systems emitting eye-safe radiation at 1645 nm. High brightness, narrow bandwidth diode laser modules at 1532 nm are used for resonant pumping, providing an absorption efficiency of 96%. Comparison with broadband diode pumping at 1455 nm shows an increase of the pumping efficiency by a factor of 2.5, leading to an optical efficiency of more than 25% in cw and 10 % in Q-switched mode under cw pumping. In addition, dual-wavelength resonant pumping of the Er:YAG laser is investigated.