Silicon based optical devices - photonic applications of anisotropically nanostructured silicon

Anisotropic nanostructuring of bulk silicon (Si) wafers leads to a significant in-plane optical anisotropy of single porous silicon (PSi) layers. Additionally a variation of the etching current in time allows a controlled modification of the porosity along the growth direction and therefore a three-dimensional variation of the refractive index (in-plane and in-depth). This technique can be important for photonic applications since it is the basis of a development of a variety of novel, polarization-sensitive, silicon-based optical devices: retarders, dichroic Bragg reflectors, dichroic microcavities and planar Si-based polarizers. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.