Low index electro-optic sol-gel materials - art. no. 602006

Polymeric electro-optic materials have made significant progress in increasing electro-optic co-efficient, enhancing temporal stability, and lower optical loss at operating wavelength. To fully realize the electro-optic activity in a waveguide device, appropriate cladding materials need to be designed carefully and a compatible fabrication process should be developed accordingly, which has been challenging and tedious. It would be desirable if glass-based optical fiber or silica substrate can be utilized as parts of device materials. The challenge is to match the relatively lower refractive index of fiber and silica substrates. Thus, a low refractive (similar to 1.44) of electro-optic material was designed. The efforts include the synthesis and characterization of the low index host materials via sol-gel process and silanization of a chromophore with large hyperpolarizability. In this study, an electro-optic sol-gel material with a refractive index similar to 1.44 at the wavelength of 1.55 mu m was developed. It was highly processible and compatible with glass-based fiber or silica-based materials. An interdigitated electrode configuration is designed and a substrate with such a configuration was fabricated. Combined with the in-situ SHG monitoring setup, poling process can be readily monitored and optimized. The r(33) obtained at the wavelength of 1.3 mu m is 19 pm/V. Thus, it becomes possible to design optical devices using glass-based fiber or silica substrate as part of the device structure, which could simplify the material and process development.