Integrated optical single-mode waveguide structures in thin glass for flip-chip PIC assembly and fiber coupling

Abstract

Glass integrated single-mode waveguides were fabricated by ion-exchange in large panel-size low-cost display glass. Propagation losses of 0.059 dB/cm (at 1550 nm) were achieved and a high process homogeneity across a panel was shown by comparison of 25 waveguides. For the first time, 12 spiral-shaped single-mode waveguides with a length of more than 2 meter were integrated in glass. Furthermore, in-plane evanescent field coupling tests were conducted to achieve first optical functions on large sized glass. To achieve higher integration density and more flexible routing, this work presents a layout-based approach to reduce bend radii without increasing propagation losses. Also without changing process parameters, selectively buried waveguides were manufactured to enable localized areas for out-of-plane coupling from EOCB to flip-chip PIC. These results provide a basis for a novel coupling concept - gradient index surface coupling (GISC).