[16a-C301-1~9] 4.4 Opto-electronics

▲ [16a-C301-7] Fabrication of sol-gel derived hybrid glass-ceramic rib waveguides on SiO₂-HfO₂-ZnO thin films

〇(D)Subhabrata Ghosh¹, Shivakiran Bhaktha B.N.¹ (1.IIT Kharagpur)

Keywords:Waveguides, Glass-ceramics, UV-lithography

We report on sol-gel fabrication of rib waveguide structures on 70 SiO₂ - 28 HfO₂ – 5 ZnO (mol %) hybrid ternary glass-ceramic waveguides on silica-on-silicon substrate. Initially, 70 SiO₂ – 28 HfO₂ – 5 ZnO (mol %) planar waveguide films are prepared by sol-gel method and dip-coating technique. Rib waveguides are fabricated by UV-photolithography followed by wet chemical etching processes. Planar waveguides are spin coated with photoresist, soft-baked, and exposed to a UV-lamp radiation using a photomask designed for this purpose. Rib waveguide structures are fabricated after development of photoresist followed by wet chemical etching using buffered hydrofluoric acid solutions. The formation of HfO₂ nanocrystals along with ZnO is also observed. Optical characterizations of planar waveguides are performed by lab-built m-line spectroscopy. These waveguides also exhibit low-loss (0.3 - 0.6 dB/cm @ 632.8 nm) which makes them a promising candidate for integrated optical device applications.