Electro-optic polymer light modulator based on attenuated total reflection

An improved ATR modulator consisted of a prism-metal-EQ-polymer-metal structure is presented. Unlike the ATR modulator conventional, we change the working interior angle from the surface plasmon resonance to a guided wave resonance. Since the propagation constant is much more sensitive to the electrically induced refractive index change in the poling polymer layer for a guided mode than a surface plasmon mode, so the drive voltage can be accordingly decreased. In our recent experiment, an ATR modulator with 1 GHz bandwidth and a modulation index of 10% at a driving voltage of 40V has been demonstrated.