Electro-optic waveguide with conductive chromophore contained polymer cladding

Abstract

Polymer electro-optic (EO) waveguides are key component of high performance electro-optic switches. Recently, EO chromophore and host polymer matrix are investigated to get high EO coefficient (r₃₃) and fabricate waveguide structures. To realize high r₃₃, chromophore density in host polymer matrix must be increased. However, high loading density results in lowering of resistivity of EO material. It becomes a problem when chromophore is poled in waveguide structure and EO modulator is worked at low frequency. In this case, EO material is sandwiched by other cladding materials but usually these materials have low conductivity compared with EO material. It means effective electric field applied to EO material and r₃₃ is reduced by cladding material layers. To improve these difficulties, we proposed new chromophore contained polymer material as cladding material of EO waveguide. Addition of EO chromospheres (6 wt %) increase conductivity to 10⁶~10⁷ Ω•m. The value is comparable or above to EO materials. We also present fabrication results of EO ridge waveguide with the chromophore contained cladding polymer.