Fabrication of three-dimensional photonic crystals with multi-layer photolithography

We have developed a new approach for the fabrication of three-dimensional photonic crystals based on multi-layer photolithography. This method, which uses commercially available photoresist, allows parallel fabrication of three-dimensional photonic crystals, and possesses the flexibility to create a variety of different lattice arrangements and the freedom of arbitrary defect introduction. We describe in this work how this method is derived from mature two-dimensional photolithography and demonstrate it with the fabrication of multi-layer woodpile structures with and without defects as well as other unique three-dimensional microstructures.