nanowires in fibers - a base for mid-IR all-solid cladding hollow core fibers

• Applicant: Professor Dr. Markus A. Schmidt
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 315131181

The efficient transportation of electromagnetic energy to desired locations clearly represents an essential feature of any practically relevant photonic system. Such guiding is typically achieved by waveguides (WGs) relying on transversely confining the light wave inside a core. The most prominent WG example is the silica-based optical fiber, which is the backbone of telecommunications and mostly operates at near-infrared (near-IR) wavelengths or in the visible.One particular interesting spectral domain, severely lacking of efficient WG solutions is the mid-IR (2.5 to 25 µm). This domain refers to photon energies below the electronic transitions of almost all materials and is attractive from both the scientific as well as from the application point of view. Mid-IR spectroscopy allows identifying low concentrations by molecular fingerprints in biology, medicine and environmental science. Mid-IR spectroscopy is also employed for explosive detection, within healthcare and for thermal imaging. Important gas lasers operate in the mid-IR such as the CO2-laser - the most employed laser worldwide. A strong demand for mid-IR WGs from the nonlinear community has grown during recent years due to promising applications in high-harmonic generation or in frequency-comb based metrology. Many of todays used mid-IR devices consist of complex, unmovable and cost-intensive setups, having prevented many mid-IR applications from being widely used. A low-loss and flexible WG solution, which does not exists for this spectral domain at the moment, would have immense impact in various fields. Within this proposed project entitled - nanowires in fibers: a base for mid-IR all-solid cladding hollow core fibers - two novel types of mid-IR hollow core fibers with unique cladding structures are to be explored. These all-solid cladding fibers are either based on indefinite metamaterials or on the photonic band gap effect. Both structures will be composed of all-solid claddings surrounding empty cores, making this kind of fiber design unique. This investigation will lead to new physical effects and will pave the way for novel mid-IR devices in a spectral domain beyond that of regular silica fibers. The research output of this proposal is of interdisciplinary origin and will have impact in various areas such as biophotonics, ultrafast optics, spectroscopy and gas lasers.

• DFG Programme: Research Grants