Epitaxial layers of KY 1−x−yGd xLu y(WO 4) 2 doped with Er 3+ and Tm 3+ for planar waveguide lasers

Abstract

Here we show the results we obtained in the fabrication of planar waveguide lasers based on monoclinic double tungstates doped with Er 3+ and Tm 3+. We have successfully introduced these ions into the lattice matched KY 0.59Gd 0.19Lu 0.22(WO 4) 2 epitaxial layers grown on KY(WO 4) 2 substrates without loss of optical quality and keeping a high refractive index contrast between the epitaxial layer and the substrate. We characterized the waveguiding properties of these epitaxial layers at λ = 632.8 nm by dark modes spectroscopy, and we showed that these waveguides can support several TE and TM modes. Spectroscopic characterization of the active lanthanide ions in these crystals is also presented.