Unprecedented highest electro-optic coefficient of 226 pm/V for electro-optic polymer/TiO2 multilayer slot waveguide modulators

Abstract

We investigated the electrical properties and optical quality of two layers a titanium dioxide (TiO₂) selective layer and a sol-gel silica cladding layer for use as coating layers for nonlinear optic (NLO) polymers in electro-optic (EO) polymer/TiO₂ multilayer slot waveguide modulators. We used a simple ellipsometric reflective technique developed by Teng and Man to measure the electro-optic (EO) coefficients of poled thin films of an EO polymer in an EO multilayer device. The Pockels coefficient was enhanced up to 226 and 198 pm/V at wavelengths of 1.31 and 1.55 μm, respectively, when optimally poled with TiO₂ and a sol-gel silica cladding.

Analysis of efficiently poled electro-optic polymer/Tio2 vertical slot waveguide modulators

“…In this calculation, we assumed that the in-device EO coefficient r 33 (70 pm/V) was same for both the TiO 2 slot waveguide modulators and the standard modulator. In the actual modulator devices, the in-device EO coefficient for the TiO 2 slot waveguide modulator is higher than that for the standard modulator, which resulted in a lower V π L e product because the poling efficiency of the EOP layer was improved by the TiO 2 and SG layers [17]. It was also difficult to pole 0.3-0.6-μm-thick EO polymers without the TiO 2 and SG layers because of dielectric breakdown at lower poling voltages of o 100 V at a glass transition temperature of 150°C.…”

“…In this modulator, the enhanced conductivity of the SG silica under Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/optcom cladding realized efficient poling of the EOP with a selective TiO 2 layer. We also demonstrated high EO coefficients of 226 and 198 pm/V at wavelengths of 1.31 and 1.55 μm, respectively, for an efficiently poled high refractive index EOP film of SEO100 deposited on a TiO 2 selective layer and SG silica cladding [17]. In this paper, we analyze the advantages of EOP/TiO 2 slot waveguide modulators for further reduction of the V π L e product when compared with hybrid EOP/SG silica waveguide modulators.…”

Biopolymers in optoelectronics

“…1,2 There are new variations of this material, such as SEO250, for which an r 33 of 250 pm/V has been reported. 2 This has led to low device operational voltages.…”

Design and preparation of novel Diels–Alder crosslinking polymer and its application in NLO materials

“…Else, the development of novel EO devices including organic EO modulator, optical switch, terahertz detectors and so on is also very fast. Lots of prototype devices based on this kind of materials have been designed and prepared in the area of scientific research [11][12][13][14][15]. Unfortunately, seldom of these devices prepared by organic EO polymers have been used in commercial areas, due to the poor long term stability of organic EO polymers, which can determine the production process and service life.…”