Hybrid silicon organic high speed electro-optic phase shifter

Abstract

We study a hybrid silicon organic high speed electro-optic phase shifter based on polymer infiltrated P-S-N ("S" refers to the slot) diode capacitor structure. This optical phase shift is realized based on index perturbation both inside the slot via Pockels nonlinearity and within the silicon ridges via the free carrier effect (carrier depletion). The combination of the polymer diode capacitor configuration with the low aspect ratio slot waveguide system leads to a promising method of constructing sub-THz speed optical modulators without sacrificing either modulation efficiency or energy consumption. By optimizing the waveguide geometry in terms of balancing effective index shift and device speed, at least 269 GHz bandwidth can be achieved with a high modulation efficiency of 5.5 V-cm when the diode capacitor is reverse biased by an external radio frequency (RF) voltage signal between the electrodes (optical propagation loss is acceptably low at 4.29 dB). © 2013 Copyright SPIE.