Abstract

Advances in laser technology continually rely on the development of novel coherent light sources in new temporal and spectral regions. Combined with nonlinear frequency conversion techniques including second-harmonic-generation (SHG), sum-frequency-mixing, optical parametric generation, amplification, and oscillation, such new sources can provide unprecedented capabilities in previously inaccessible temporal and spectral regions across the UV, visible and IR [1]. A particularly important cornerstone of laser technology over the past decade has been the generation of green radiation, for example, as workhorse for pumping of Ti:sapphire and other tunable laser systems. In the continuous-wave (cw) regime, the current status of this technology relies almost exclusively on internal frequency doubling of cw Nd-based solid-state lasers [2]. However, the high cost and design complexity of such systems point to the need for the development of alternative techniques offering simpler design, improved practicality, and lower cost. By taking advantage of the major advances in fiber laser technology and improved nonlinear materials, it is now possible to develop a new generation of efficient, high-power and practical cw green sources in compact, portable and cost-effective design using simplified nonlinear frequency conversion techniques. Here, we present such a source based on simple single-pass SHG of a cw ytterbium (Yb) fiber laser in MgO:sPPLT, providing a single-frequency cw power of as much as 9.64 W at 532 nm with a conversion efficiency of 32.7%.

© 2009 IEEE