Spectroscopy, Modeling, and Performance of Erbium-Doped Ta$_{2}$O$_{5}$ Waveguide Amplifiers

Abstract

The design, fabrication, spectroscopic characterization, and performance of an Er:Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> rib waveguide amplifier is described. Rib waveguides with low loss (<; 0.65 dB/cm at 1600 nm) were obtained. Their absorption spectrum was measured and McCumber theory was employed to obtain the emission spectrum, leading to the absorption and emission cross sections. Numerical modeling for gain optimization in Er:Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> waveguide amplifiers is presented, employing the experimentally determined parameters. Finally, net optical gain of 2.1 dB/cm at 1531.5 nm is demonstrated in a 2.3 cm long Er:Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> rib waveguide when pumped with 977 nm laser diode, and compared with simulations to deduce the extent of upconversion.