Microwave and optical design optimatization of polymer phase modulators with over 40 GHz BW

Design and performance optimization of phase modulators is presented by considering both microwave and optical characteristics. Performance modeling is conducted using OptiBPM for beam propagation method of optical waveguide and finite element method using HFSS for driving electrode design. The optical waveguide core realized using electro-optic (EO) polymer PMMI-CPO1 with a refractive index n₁=1.63, EO coefficient r_eo=70 pm/V, RF dielectric constant ε_r1=3.15, and loss tangent tanδ₁=10^-3 that is embedded in a cladding polymer of NOA65 with n₂=1.51, ε_r2=3.2 and tanδ₂=2.2×10^-2. A phase modulator with an input half-wave voltage of 8 V and a bandwidth of 43 GHz operating at the wavelength of 1.55 μm for RF and optical interaction length of 1.3cm.