HfO2-based Platform for High Index Contrast Visible and UV Integrated Photonics

We study HfO 2 /Al 2 O 3 composites for high-index visible/UV photonics, exhibiting material losses of < 3.0 dB/cm and n = 1.96 at λ = 405 nm. Single-mode waveguides losses are 15.3 ± 1.9 dB/cm for λ = 405 nm (2.3 ± 0.1 dB/cm for λ = 730 nm), likely limited by sidewall roughness scattering.