Submicrometer resolution Yablonovite templates fabricated by x-ray lithography

We report the fabrication and optical characterization of diamond-like photonic structures with 1.3 μm lattice constants. In analogy with the first Yablonovite obtained by a mechanical drilling of a dielectric material, the structures are fabricated in poly(methylmethacrylate) resist using three consecutive exposures to an x-ray beam through a triangular lattice of holes. Up to six crystal periods are obtained in a 6.2-μm-thick resist. The measured reflection and transmission spectra show well contrasted photonic gaps in agreement with numerical simulations. This demonstrates the good optical quality of the structures that can be used as porous templates for transferring the diamond-like pattern to high-refractive-index dielectrics or metals.