Research Program

In the GRK 2101, novel waveguide structures with enhanced performance and fundamental aspects of propagation and interaction of light with extreme properties in structures will be discovered. This can be achieved by using novel materials as well as precise transversal and longitudinal nanoscale structuring which will result in new concepts for light confinement and guiding which can be used for new optical functionalities and applications. In order to ensure a successful mastery of the complex scope of the work the research projects are grouped in three joint research pillars:


Pillar 1 deals with the fundamental material aspects, design and realization of innovative waveguide structures with unmatched properties and functionalities. Fundamental linear and nonlinear light propagation effects in waveguide structures as realized in pillar 1 as well as the interaction of the propagating light with its environment will be mastered in pillar 2. Finally, pillar 3 will harvest the novel functionalities to realize applications with hitherto unknown precision. Each of these different aspects will be investigated in close collaboration between all the partner institutions in Canada and Germany.

Research pillar 1 - Longitudinal and transversal structured waveguides

1.1 Realization of innovative fiber structures

  • Liquid-core PCF - a new base for soliton propagation in extremely confined geometries
  • Hollow-core chalcogenide glass band gap PCFs for mid-IR applications
  • Super-continuum generation in heavy oxide fibers with artificially enhanced nonlinearity

1.2 Functionalization of optical fibers by defined (laser) structuring

  • Fiber Bragg gratings for microstructure optical fiber - towards high power mid-IR lasers
  • Mode-converters and polarization controlled optical fiber circuits - quantum encryption on fiber
  • Waveguide probed optical resonator cavities - novel spectral filter concepts embedded in fiber

1.3 Optical guiding structures in bulk materials and thin films by laser modification

  • Spatio-temporal control of ultrashort laser pulses for defined modifications inside transparent bulk materials
  • Local control of polarization states by 3D confined artificial birefringence
  • Tailoring the propagation properties in thin-film waveguides by local laser nanostructuring

1.4 Novel functional materials with tailored properties

  • Integrated, waveguide-based magneto-optical isolation using novel materials
  • Sub-wavelength scale electro-optic modulators and switches using hybrid VO2-onsilicon waveguides
  • Realization and investigation of waveguiding structures built from or embedded in periodic structures
  • Investigation of the nonlinear response of PT-symmetric effective materials

Research pillar 2 - Temporal and spatial effects in waveguides

2.1 Linear confinement of guided light waves

  • Localized edge states due to disorder
  • Light evolution in disordered photonic crystals
  • Light tailoring due to artificial defects

2.2 Light confinement inside cavities

  • Limits of topological cavity mode isolation in the strong confinement regime
  • All-optical switching and signal processing at ultra-low powers in optical cavities
  • Pattern formation and spatio-temporal confinement in coupled cavity systems

2.3 Nonlinear propagation effects of guided high intensity light

  • High field THz pulses from filaments driven by long wavelength pulses
  • Exploiting ionization induced nonlinearities in hollow core fibers for supercontinuum generation
  • High average power energetic few-cycle pulses at 2 μm wavelength
  • Compression of energetic laser pulses in large area hollow core fibers
  • Efficient Raman-shifters based on Bessel-beams
  • Spatio-temporal coupling with beams carrying angular momentum

2.4 All-optical routing and switching in waveguide networks

  • Optimization of two-dimensional geometries for the efficient routing of light
  • Blocking and switching of light in waveguide arrays using discrete spatial solitons
  • Data processing on the flight employing the interaction between pulses during their propagation
  • Bit sequence and header recognition in waveguide arrays

Research pillar 3 - Novel optical functions in waveguide components and systems

3.1 Novel fiber laser sources

  • Design and excitation schemes of multi-core amplifying fibers and their coherent combination
  • Investigation of passive and active stabilization of interferometric multi-core fiber amplifier
  • Raman gain fiber lasers for the mid-IR based on fluoride and chalcogenide fibers
  • Supercontinuum generation in the IR/MIR spectral range using ultrashort (femtosecond) pulses

3.2 Integrated quantum systems

  • Integrated quantum sources based on fiber and laser-modified waveguides
  • Quantum walks of correlated photons in a 3D laser-written waveguide lattice
  • Chip-based quantum gates for photon qubits

3.3 Smart fiber-based biosensors

  • Functionalization scheme to develop 3D optofluidic fiber devices
  • Fiber based cell-counting system and plasmonic sensor
  • Multifunctional core-shell nanowires for biosensing applications in a large spectral range
  • Spectral diagnostics and theranostic approaches at plasmonic structures in the near-infrared
  • Silicon nanostructure-decorated optical fibers: formation and optical loss optimization