We demonstrate good optical quality TiO2 thin films grown by atomic layer deposition at 120°C. The optical properties were studied using spectroscopic ellipsometry and prism coupling methods. The refractive index was 2.27, and the slab waveguide propagation loss was less than 1dB/cm at 1.53μm. A high quality resonant waveguide grating was fabricated using a thin TiO2 layer on top of a SiO2 grating.
Alasaarela, T., Saastamoinen, T., Hiltunen, J., Säynätjoki, A., Tervonen, A., Stenberg, P., Kuittinen, M., & Honkanen, S. (2010). Atomic layer deposited titanium dioxide and its application in resonant waveguide grating. Applied Optics, 49(22), 4321-4325. https://doi.org/10.1364/AO.49.004321