Laser emission with low quantum defect in $\mathrm{Yb}:\mathrm{Ca}\mathrm{Gd}\mathrm{Al}{\mathrm{O}}_4$

Abstract

It is demonstrated that 2% $\mathrm{Yb}:\mathrm{Ca}\mathrm{Gd}\mathrm{Al}{\mathrm{O}}_4$ (called CAlGO) presents favorable thermomechanical properties with a high measured thermal conductivity (${\kappa }_{\Vert c}=6.3$ and ${\kappa }_{\perp c}=6.9\mathrm{W}{\mathrm{m}}^{-1}{\mathrm{K}}^{-1}$). A laser oscillation in this material at $1016\mathrm{nm}$ is demonstrated for the first time to our knowledge while pumping at $979\mathrm{nm}$. This implies a very small quantum defect (3.5%). A simple new figure of merit that takes into account thermomechanical properties and quantum defects is proposed here to compare the resistance of materials under high-power laser pumping. Consequently, Yb:CAlGO is similar to garnets and sesquioxides in regard to laser power resistance.

© 2005 Optical Society of America