Fabrication of 2-D photonic crystal using multiple exposures

We describe a novel approach to manufacture photonic crystal-based integrated systems based on a two-step process of interferometric patterning followed by optical direct-write of the functional elements. First, the photonic crystal lattice is patterned in photoresist using interferometric lithography, producing a large-area lithographic pattern quickly and easily. Second, the defects in the lattice to implement the functional devices are created using optical direct write with a strongly focused optical beam. After patterning processes, the mask is developed and a dry-etching process is used to transfer the pattern into the substrate. This hybrid approach possesses an advantage in terms of fabrication time and cost as compared to E-beam lithography for the patterning of large-scale photonic crystal-based systems.