Growth and characterization of Yb3+ doped Y2SiO5 layers on Y2SiO5 substrate for laser applications

We report on the epitaxial growth and spectroscopic study of highly doped Y2SiO5:Yb3+ (YSO:Yb) thin films on YSO substrates. The realization of Ge, La and Gd-codoped high quality thin films, with thickness up to 100 μm, is demonstrated. YSO:Yb layers have their fluorescence and absorption spectra similar to the bulk ones, with a globally higher crystalline quality. The Yb3+ lifetime evolution exhibits a particularly slow decrease with Yb doping, proof of a low extrinsic quenching centers concentration. The refractive index increase with respect to dopants concentration is measured, and a phenomenological law is proposed. Such highly doped YSO:Yb layers could be an interesting alternative for active integrated optics or laser devices.