Progressive Poling of Large Area, High r33 Electro-Optic Polymer SEO100c

Michael Maurer,Christopher Middlebrook,Evan Gawron

doi:10.3390/app11178108

Abstract

SEO100c, an EO-polymer, has been reported of having an r33 in excess of 100 pm/V. Experimental poling research was performed on rib waveguide modulator for device design and development. Reported is the determination of the impact that temperature and voltage have on the poling of a SEO100c waveguide device in order to maximize the r33 while avoiding damage to the device structure ensuring high yield in manufacture. The poling process is shown to have a nonlinear relationship between r33 and poling field aiding in the selection of achievable poling voltages for required r33 values. Device thermal stability is quantified and reported for the complete poling process and the impacts upon r33. Investigation into the possible relaxation of device r33 is measured over an extended period demonstrating desirable use within deployable devices.

Highlights

Electro-Optic (EO) waveguide modulators are essential in optical communications to convert electrical signals to optical signals
The majority of commercial EO modulators utilize lithium niobate which has a maximum r33 tensor of 30.8 pm/V [2] limiting the reduction in Vπ for most modest laser power
Alternative to lithium niobate are electro optic polymers, which consist of a polymer matrix, commonly polycarbonate or PMMA, and nonlinear EO chromophore molecules [3]

Summary

Introduction

Electro-Optic (EO) waveguide modulators are essential in optical communications to convert electrical signals to optical signals. The contact poling method results in the electric field being distributed between the cladding and core layers, requiring a higher applied voltage to get equivalent poling results This higher voltage introduces additional risks to the poling process as the high voltage may cause arcing between electrodes or cause a dielectric break down in any of the device layers. Inherent to the polling process of EO-polymers is the risk of dielectric breakdown This risk is introduced by the combination of heating the polymer to the glass transition temperature which lowers the breakdown voltage while applying a high strength field to the device. A polymer modulator made from commercially available products demonstrates the progress that has been made in EO polymer design

Device Geometry

Poling of Electro-Optic Polymers

Poling Electric Field Strengh Results

Temperture Dependence on Poling Efficency