Rapid Fabrication of Three-Dimensional Woodpile Photonic Crystals by Means of Two-Photon Photopolymerization

Two-photon photopolymerization (TPP) of femtosecond laser is a promising method to fabricate three-dimensional woodpile photonic crystals (PCs). We build micro-fabrication system based on the principle of TPP. Three-dimensional woodpile PCs consisting of in-plane rod distances ranging from 1000nm to 2000nm are fabricated by focusing femtosecond laser in photosensitive liquid resin ORMOCER. The properties of the PCs are also discussed, and fundamental photonic band gaps in middle-infrared range are measured, whose in-plane rod distances are 1500nm and 2000nm. Three-dimensional woodpile PC devices with desired defects, such as cross-waveguide and micro-laser structures, are introduced easily by TPP. We fabricate the three-dimensional woodpile PCs in the liquid resin at the fast scanning speed of 120μm/s.