Integration of electro-optic polymer modulators with low-loss fluorinated polymer waveguides

We have demonstrated a hybrid Mach–Zehnder optical modulator consisting of a large-core, low-loss fluorinated passive polymer waveguide and an electro-optic (EO) polymer waveguide. The combination exhibits low fiber coupling loss to the passive waveguide and reduced transmission loss because the EO polymer waveguide is used only in the active region. The two waveguides are connected by vertical tapers that permit low-loss adiabatic coupling between the two modes. The half-wave voltage and the insertion loss of the fabricated modulator are 3.6 V and 6 dB, respectively, at a wavelength of $1.55 \mathit{\mu }\mathrm{m}$. The estimated coupling loss with the standard single-mode fiber is $\sim 0.5 \mathrm{dB}$.