We investigate methods for actively tuning two-dimensional photonic crystal devices by modulating the index of refraction of the constituent materials. The index of refraction is modulated by infiltrating liquid crystals into a photonic crystal lattice of air cylinders in silicon. Moreover, the orientation of the liquid crystal molecules within the cylinders is actively modulated in order to induce a change in the dielectric tensor; thereby, tuning the optical properties of the photonic crystal. We validate and characterize the tunability of these devices both experimentally and with three-dimensional finite-difference time-domain method simulations. Furthermore, we integrate these tunable devices to demonstrate their enhancement of WDM photonic crystal applications.