Photonic crystal materials realized by high aspect ratio micro-rod arrays

This paper reports on the fabrication and optical properties of a novel type of photonic crystal structure. The structure consists of an array of Si micro-rods with a very high aspect ratio (1∶25) on a Si substrate. The fabrication is based on the creation of macroporous Si by a wet-chemical etching technique. Subsequent filling of the pores and selective etching of the Si substrate creates a needle array of the filling material. Up to now we realized rod arrays with poly-Si filled rods. Simulations show that these rod arrays offer unique optical properties and can be used as optical bandgap materials.