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Three-dimensional (3D) photonic crystals (PCs) are crystalline materials where the refractive index is periodically modulated on a length scale comparable to the light wavelength of interest. Interference of the light waves scattered from the dielectric lattice (ie, Bragg scattering) leads to omnidirectional stop bands or photonic band gaps (PBGs), which are analogous to the electronic energy band gaps in a semiconductor. 1, 2 The bandwidth and the frequency of the PBG are determined by the refractive index contrast between the high and low (typically air) dielectric materials, the structural symmetry and periodicity, and the filling fraction and morphology of high-refractive-index materials. Photonic crystals with a large, complete PBG are highly desired, which act like an optical trap to reflect incident light from any direction at a certain frequency range of light. Thus, controlled functional structures can be engineered into …