Polymer-based electro-optical modulators are, generally, applicable to many fields but their applications to analog optical links and silicon photonic integrated circuits are specifically emphasized in this dissertation. This dissertation aims to improve the linearity characteristics of polymer-based electro-optic modulators for their practical application in high speed analog optical links. Domain-inversion technique is employed to linearize a two-section Y-fed directional coupler modulator. The spurious free dynamic range as high as 119dB/Hz2/3 has been demonstrated with 11dB enhancement over the conventional Mach-Zehnder modulator at low frequency. For high speed modulation, a traveling wave electrode with low RF loss and large bandwidth is designed and installed in a linearized Y-fed directional coupler modulator. The spurious free dynamic range has been measured in the range of 110±3dB/Hz2/3 at 2~8GHz frequency. For digital application of polymer-based electro-optic modulators, a hybrid silicon photonic crystal waveguide modulator was investigated with focus on size-reduction and electro-optic efficiency enhancement. The slow group velocity of photonic crystal waveguides promises two orders of magnitude size-reduction in device footprint compared with the conventional strip waveguide. Infiltration of an electro-optic polymer into the slot waveguide can infuse silicon with nonlinear optical properties. To actualize these benefits of a hybrid silicon photonic crystal waveguide modulator, nano-fabrication process was developed and optimized in this work. / text