Fabrication of 3-D photonic crystals typically has relied either on lithography or on self-assembly techniques, but that gap could be bridged by a method described in the Oct. 21 issue of Applied Physics Letters. Researchers at Riken Semiconductors Laboratory, the National Institute for Materials Science and Yokohama National University, all in Japan, formed 2-D lattices using standard lithography and applied self-alignment techniques to micromanipulate the plates into 3-D crystals. Embedded microspheres matched fiducial holes to ensure that the lattices aligned into a photonic crystal structure with a bandgap between 3 and 4 µm.