Pulsed laser deposition of phospho-tellurite glass thin film Waveguides

This paper introduces a new generation of low loss of glass thin film material, ideally suited to high bandwidth fully integrated waveguide devices deposited by pulsed laser deposition (PLD) on silica substrates. Due to high solubility of rare earth ions in the phosphate and tellurite glasses, it is possible to deposit thin films with high erbium ion concentration from a bulk phospho-tellurite glass. High quality phospho-tellurite (TP) thin films up to 2 μm thickness with less than 0.05 dB/cm propagation losses were deposited using a 193nm ArF excimer PLD system, in a low pressure oxygen atmosphere. Waveguides were fabricated using conventional photolithography and reactive ion etching. A mixture of Ar and CHF₃ gas at various flow rates and RF powers were used to produce 0.7 μm thick waveguide channel.