Abstract

In recent years, ytterbium-ion (Yb)-doped materials have been recognized having attractive potential for laser-diode (LD) pumped solid state lasers. One of the features of the Yb-doped materials is that it can incorporate very high concentrations of the Yb-ions with low concentration quenching. Highly laser ion-doped materials with short absorption length permit the use of thin gain media with high pump absorption efficiency. The thin media are useful for high efficiency oscillation by high intensity pumping, i.e., LDs with low beam quality can be used as pump sources with high mode-matching efficiency between the laser beam and the pump beam. For example at room temperature, the highest efficiencies, which close to the laser quantum limit of 91% and are the highest in the lasers to our knowledge, are obtained by continuous-wave (CW) microchip Yb:YAG lasers with a high ion concentration of 20 at.% by high intensity pumping [1]. Although the pump source was a Ti:sapphire laser, these results suggest that these efficiencies can be also obtained from LD pumped CW lasers with higher Yb-ion concentration materials, such as the stoichiometric Yb-doped materials, in which Yb-ion concentration is the highest in the Yb-doped materials.

© 2013 IEEE