High efficiency in-band pumped Tm- and Ho-doped 2-μm solid-state lasers

Abstract

The expansion of laser sources operating at 2-3 μm is motivated in large by strong absorption in atmospheric gases, liquid water, and plastics, critical for applications in remote sensing, soft and hard tissue surgery, and materials processing. 2-μm novel solid-state lasers based on Tm3+-doped ceramics (Lu2O3 or Y2O3) or YAP crystals in-band pumped by a fiber laser at 1670 nm are presented in this report. CW, actively or passively Q-switch operations of the Tm3+-doped lasers are described. The Tm3+ laser characteristics are compared with parameters of an in-band fiber-laser-pumped Ho3+:YAG laser. The 2-μm output of the lasers are used to pump the Cr2+-doped ZnSe or CdSe crystals. The lasers based on the Tm3+:Lu2O3 ceramics and the Tm3+:YAP crystal are also used as pump sources for mid-IR optical parametric oscillators (OPOs) or second-harmonic generators (SHGs). The high-efficiency oscillations are obtained at 3.8-4.1 μm in the OPOs based on a fun-out PPMg:LN; the SHGs provided the repetitively-pulsed radiations at 970-983 nm.