Hybrid Electro-Optic Polymer/TiO2 Multilayer Waveguide Modulators on Mesoporous Sol-Gel Silica Cladding

Abstract

We report efficient poling of electro-optic polymer in hybrid electro-optic (EO) polymer/TiO2 multilayer waveguide modulator on mesoporous sol-gel silica cladding. The mesoporous sol-gel silica has ~nm size of porous structure with lower refractive index of 1.24, which improves poling efficiency and mode confinement in the 400nm-thick thin EO polymer film in the modulators. The cladding prevents optical absorption more efficiently from lower Au electrode. Half wave voltage (Vπ) of the modulator fabricated on the mesoporous sol-gel silica cladding is 6.0 V for the electrode length (Le) of 5-mm at 1550nm wavelength (VπLe product of 3.0 V· cm). In-device EO coefficient was 75 pm/V, using low-index guest-host EO polymer.