Open AccessEnhanced conductivity of sol-gel silica cladding for efficient poling in electro-optic polymer/TiO_2 vertical slot waveguide modulators
Author(s) -
Yasufumi Enami,
Youssef Jouane,
Jingdong Luo,
Alex K.Y. Jen
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.030191
Subject(s) - materials science , poling , cladding (metalworking) , polymer , optics , refractive index , electrode , conductivity , optoelectronics , waveguide , slot waveguide , composite material , dielectric , silicon photonics , ferroelectricity , silicon , chemistry , physics
We report the enhanced conductivity of sol-gel silica under-cladding for efficient poling of electro-optic (EO) polymer in a hybrid EO polymer/TiO2 vertical slot waveguide modulator. The electrical volume conductivity of sol-gel silica cladding increases approximately 30 times when the calcining time of the cladding layer is critically reduced to 45 minutes, which increases the in-device EO coefficient of the 600-nm-thick EO polymer film in modulators and reduces the lower halfwave voltage (Vπ) of the modulators. The lowest driving voltage (Vπ) of the TiO2 slot waveguide modulator is 2.0 V for an electrode length (Le) of 10 mm and wavelength of 1550 nm (VπLe = 2.0 V·cm) for the low-index guest-host EO polymer SEO125. The optical propagation loss is reduced to 7 dB/cm.