Fabrication of highly ytterbium (Yb 3+)-doped YAG thin film by pulsed laser deposition

Abstract

As an infrared laser waveguide, the epitaxial growth of 5 μm -thick ytterbium (Yb 3+)-doped yttrium aluminum garnet (YAG) thin films on YAG(1 1 1) (Y 3Al 5O 12) substrate has been demonstrated by pulsed KrF laser deposition with post-annealing. Highly Yb 3+-doped (up to 100 at.%) YAG films have been epitaxially grown on YAG(1 1 1). The crystalline quality of the grown films does not degrade even with high doping concentrations of Yb 3+ ions up to 100 at.%. The roughness (root mean square) of the film is measured as 1.27 nm without droplets or particulates. The optical properties of these films have been characterized in terms of absorption spectra, fluorescence spectra and fluorescent lifetime. The refractive index of n at 1.03 μ m is measured to be 1.851±0.0141 for 50 at.% Yb 3+:YAG. An emission lifetime of 0.90±0.01 ms is obtained for 1.03 μ m transition.