Institute of Applied Physics, Abbe Center of Photonics, Friedrich-Schiller-Universität, Jena, Germany
Fraunhofer-Institute for Applied Optics and Precision Engineering IOF, Jena, Germany
Max Planck School of Photonics, Germany
Integration of two-dimensional materials in optical systems for nonlinear optics, sensing, and single photon sources
Many of crystalline two-dimensional materials have been discovered in the last years, a lot of which exhibit interesting physical properties. They are a natural addition to the set of common of optical materials and can be used to functionalize classic micro- and nanooptical systems. Moreover, they grow in a crystalline manner on many substrates commonly used in photonics, such as SiO2, Si, and Al2O3. From an optics point-of-view transition-metal dichalcogenides  (TMCs) and hexagonal Boron-Nitride  (hBN) are among the most interesting materials. TMCs are direct semiconductors with bandgaps in the visible. They exhibit unusually high refractive indices, strong and highly sensitive fluorescence , and large nonlinear coefficients . Their light-matter-interaction behaviour is dominated by highly stable excitons and valley-polarization . hBN, on the other hand, is a large bandgap dielectric, which exhibits bright room-temperature defect-state single-photon emitters [6, 7].
I will discuss some strategies to integrate 2D-materials with coatings, resonators, and waveguides. We use an IAPVD-based low-temperature technique to embed 2D-materials in planar dielectric systems , such as optical coatings and Bragg-cavities, without degradation of their properties. There we have studied the strong coupling of excitons to cavity polaritons and their coupling to external magnetic fields  as well as the resonator-based enhancement of single-photon-emitters . We also show, that they can be integrated in optical systems  for usage in space-based quantum key distribution networks . I will also discuss experiments, where the material is coupled to all-dielectric nanoscale resonators ; paving the way for active nanoscale photonic structures. Another topic is the integration of 2D-materials with optical fibers and nanophotonic waveguides. These waveguides enhance light-matter interaction radically and enable sensing applications and applications in low-power nonlinear optics.
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