Er:YGG planar waveguides grown by pulsed laser deposition for LIDAR applications

Er:YGG planar waveguide amplifiers (PWAs) are promising candidates to meet the needs of greenhouse-gas differentialabsorption LIDAR applications. We report pulsed–laser-deposition growth of this doped crystal and net-gain performance (internal gain ~2 dB/cm for 0.7-at.% Er-doping) in a 0.9-cm-long uncoated single-pass PWA. Rapid fabrication is also demonstrated with optimized parameters, where crystal growth rates approaching 20 microns/hour have been realized. We compare Er-doping concentrations ranging from 0.5 at.% - 4 at.%, and report on their spectroscopic properties. Furthermore, we show the ability to tailor the deposited crystal properties, controlling the waveguide and gain characteristics. Finally, we discuss the spectroscopy and potential performance of this relatively unstudied material for PWAs in the eye-safe regime.