The use of engineered nanoscale lattice structures, or photonic crystals (PhC), to control light energy propagation was pioneered by Yablonoivitch and S. John. Their objective was to inhibit spontaneous emission and study light localization in periodic dielectric structures. They realized that the periodicity of the engineered lattice and the materials it comprises define energy propagation regimes in the crystal-like structure. A typical example of a one-dimensional (1D) PhC is the well-studied distributed Bragg reflector (DBR), comprised two or more different optical materials stacked on top of each other in a periodic fashion. Although these DBRs are considered a 1D class of PhCs, they were studied for several years before the findings of Yablonoivitch and John. The chapter discusses the photonics crystal theory and modeling of electromagnetic wave interaction with PhCs. The critical dimensions obtained from modeling are used for PhC fabrication. The chapter describes top-down and bottomup fabrication techniques used to achieve periodic nanoscale lattice features.