High-Extraction-Rate Ta 2 O 5 -Core/SiO 2 -Clad Photonic Waveguides on Silicon Fabricated by Photolithography-Assisted Chemo-Mechanical Etching (PLACE).

We demonstrate high-extraction-rate Ta 2 O 5 -core/SiO 2 -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 Ta 2 O 5 waveguides have shown the quality factors to be above 10 5 near 1550 nm. The demonstrated Ta 2 O 5 waveguides and their fabrication method hold great promise in various cost-effective applications, such as optical interconnecting and switching.