High-Extraction-Rate Ta₂O₅-Core/SiO₂-Clad Photonic Waveguides on Silicon Fabricated by Photolithography-Assisted Chemo-Mechanical Etching (PLACE)

Abstract

We demonstrate high-extraction-rate Ta2O5-core/SiO2-clad photonic waveguides on silicon fabricated by the photolithography-assisted chemo-mechanical etching technique. Low-confinement waveguides of larger than 70% coupling efficiency with optical fibers and medium propagation loss around 1 dB/cm are investigated in the experiment. Monolithic microring resonators based on Ta2O5 waveguides have shown the quality factors to be above 105 near 1550 nm. The demonstrated Ta2O5 waveguides and their fabrication method hold great promise in various cost-effective applications, such as optical interconnecting and switching.

Keywords

• tantalum pentoxide
• femtosecond laser direct writing
• high extraction rate
• low scattering loss
• microring resonator