Three-dimensional optical lithography for photonic microstructures

Photonic-crystal devices must be precisely aligned within a photonic-crystal lattice. Rapid and flexible optical fabrication of a device embedded in, and in registration with, a 3D photonic crystal is demonstrated. Holographic lithography (see figure) is used to define the underlying periodic microstructure in a single exposure, and two-photon laser writing to create localized structural defects. An intermediate latent image of the photonic crystal is used to align the two exposures.