The doping of silica yields additional degrees of freedom to vary the optical parameters of index guided and band gap controlled microstructured optical fibers (MOFs). Aside from the widely investigated rare earth doped microstructured fibers for lasers also the integration of conventionally doped structural elements with passive functions into MOFs allows to enhance effectively the optical performance of such fibers. We report on progress in preparation of microstructured fibers with air holes and solid structural elements composed of germanium and fluorine doped silica materials. The microstructured fibers were prepared by stack-and-draw technology. The starting materials are preform rods and tubes with graded dopant concentration prepared by MCVD and sintering technology. They were elongated to millimeter dimensions before packaging to final MOF preforms. We prepared MOFs with both holey core and holey cladding. The microstructuring of the holey cladding is achieved with fluorine doped capillaries. Several applications have been investigated. The high photosensitivity of germanium-silica MOFs makes possible the inscription of Bragg gratings with high efficiency. In fiber evanescent field sensors, such microstructured fibers improve the overlap between the propagating light field and the analyte and allow therefore an increased sensitivity e.g. for gas sensing with optical fibers. Solid MOFs with multiple cores in a highly precise array arrangement can been investigated as a model system for the study of nonlinear dynamics in discrete optics.© (2007) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.