Two-dimensional photonic crystals by focused-ion-beam etching of multilayer membranes

We present an approach for two-dimensional photonic crystal fabrication in prestructured multilayer membranes. We show that well-defined structures with submicronic periodicity can be created by focused-ion-beam etching through the membranes. A photonic band gap around 1.5 μm is observed by spectral measurements, in agreement with theoretical simulations. Further improvements are also proposed.