Reflection and transmission characterization of a hexagonal photonic crystal in the mid infrared

We report on the fabrication of a hexagonal photonic crystal of air cylinders in silicon and its characterization in the mid infrared. The structure was obtained in electrochemically etched macroporous silicon. Simultaneous reflection and transmission measurements were undertaken for the two main crystal orientations and two polarizations. The first four orders of photonic band gaps were identified by transmission attenuations and reflection peaks. A complete photonic band gap was observed at 5.8 mu m, in good agreement with numerical calculations. The measured reflection characteristics of the crystal demonstrate the application possibilities of photonic crystals. (C) 1998 American Institute of Physics.