LITHOGRAPHIC BAND-GAP TUNING IN PHOTONIC BAND-GAP CRYSTALS

We describe the lithographic control over the spectral response of thr ee-dimensional photonic crystals. By precise microfabrication of the g eometry using a reproducible and reliable procedure consisting of elec tron beam lithography followed by dry etching, we have shifted the con duction band of crystals within the near-infrared. Such microfabricati on has enabled us to reproducibly define photonic crystals with lattic e parameters ranging from 650 to 730 nm. In GaAs semiconductor wafers, these can serve as high-reflectivity (>95%) mirrors, Here, we show th e procedure used to generate these photonic crystals and describe the geometry dependence of their spectral response. (C) 1996 American Vacu um Society.