Polymeric electro-optic modulator based on 1×2 Y-fed directional coupler

We have demonstrated a polymeric electro-optic modulator based on a $\text{1×2}$ Y-fed directional waveguide coupler. The symmetric geometry of the $\text{1×2}$ Y-fed directional coupler provided the modulator unique characteristics of intrinsic 3 dB operating point and two complementary output ends. A low switching voltage of 3.6 V and a high extinction ratio of 26 dB were obtained with the modulator operating at a wavelength of 1.34 μm. The modulator was fabricated with a novel electro-optic polymer that was synthesized from polyurethane cross-linking with a chromophore.