In this project, novel hollow-core fibers for the mid-infrared spectral range will be investigated theoretically as well as experimentally. This is a type of fiber which has not been investigated so far and which consists of metamaterial claddings of metallic nanowires or of dielectric high index wires which induce the formation of so-called photonic bandgaps. Both cladding types encircle a hollow core and can potentially guide light in the air core. These types of fibers may operate in a much broader bandwidth than conventional hollow core fibers and are very easy to fill with liquid due to the lack of air holes in the cladding region. The tasks of the IPHT lie here in the areas of fiber design, fiber fabrication, simulation, characterization and application of the fibers in the field of biophotonics (e.g. in-fiber spectroscopy). First calculations show very promising results in the field of plasmonic band gap guiding. Furthermore, there are isolated references in the literature to the positive influence of the high refractive index on the waveguiding in a defect core. The fibers to be investigated here have never been realized anywhere in the world, thus providing the IPHT with an opportunity to establish itself in the currently heavily researched field of hollow core fibers.
In all likelihood, the IPHT will be able to solve all of the problems described above on the basis of its many years of expertise and its very extensive infrastructure, especially with regard to fibers. In this context, the fiber production (realization of precisely fitting fibers), the expertise of the applicant in the field of filling technology (especially for nano-holes) and the possibility of characterization by various laser sources and spectrometers are to be emphasized.

The project is funded by the DFG grant number SCHM 2655/8-1; AOBJ 631174.