Polarization insensitive electro-optic polymer modulator

Abstract

Electro-optic waveguiding polymer devices are very attractive for optical communication systems as a result of simple and potentially low-cost fabrication procedures. Several functions, such as high speed modulation or switching, have been already demonstrated. However, their polarization sensitive response precludes any actual use in optical telecommunication systems. The traditional uniform poling procedure, a prerequisite processing step for electro-optic polymer based devices whereby an electric field is applied at the vicinity of the glass transition temperature resulting in statistical polar orientation of the chromophores, is responsible for polarization sensitivity. By way of different coplanar or sandwich electrode configurations, any desired prerequisite modulation axis can, however, be imprinted onto the material resulting in the possibility of balanced TE/TM polarization efficiencies. Monolithic integration of both electrode configurations within a Mach–Zehnder modulator is shown to result in an original polarization insensitive electro-optic polymer amplitude modulator for integrated optics. Design procedures including modeling, fabrication, as well as performance testing of the integrated sandwich and transverse electrode configurations device are discussed. The electrode configuration is optimized in view of ensuring both efficient poling conditions and maximal overlap of the modulation field with the active layer cross section.