Polymer Planar Bragg Gratings Based on Cyclic Olefin Copolymers

This work is dedicated to the further development of polymer planar Bragg gratings based on cyclic olefin copolymer platforms as there are still open queries with respect to the employed fabrication processes and also significant potential for new application fields. Therefore, a part of this thesis examines and discusses the material properties of injection-molded cyclic olefin copolymers, with a special focus on the intrinsic anisotropy exhibited by the employed wrought material. It is found that especially near-surface waveguides and Bragg gratings, manufactured via the single-writing-step procedure, exhibit distinct position- , direction- and polarization-dependent properties. Moreover, a photochemical modification model is derived for the defined irradiation of cyclic olefin copolymers with ultraviolet radiation and subsequent thermal treatment. The model is additionally correlated to the resulting positive refractive index modifications induced by the process. Another major focus of this work is the development of novel application fields for polymer planar Bragg gratings based on cyclic olefin copolymer substrates. By means of functional coatings, hypersensitive hydrogen detectors as well as electrified photonic platforms are realized. The latter enables active tuning of the reflection signal by means of a current supply. Furthermore, robust sensor packaging approaches are paving the way towards harsh-environment application of these photonic devices, while well-designed substrate layouts enable the realization of novel pressure sensor designs. Finally, this work also demonstrates two novel waveguiding concepts, i.e., ridge-type waveguides and lattice-like waveguides.