Some of Ulf Peschel's current research activities focus on the time evolution of optical pulses in fiber systems. Together with his group "Nonlinear Optics and Nanophotonics (NONA)" and for the first time, he realized a discrete system in the time domain and investigated time discrete temporal solitons. He currently studies optical systems with balanced gain and loss, which may allow for the formation of fractal patterns and if they obey parity-time (PT) symmetry also for sudden phase transitions and unidirectional invisibility. Recently, the group observed the first PT-symmetric optical solitons. Ulf Peschel's research in the field of nanophotonics is concentrated on metamaterials, photonic crystals and plasmonic structures. Together with his co-workers he developed new methods to characterize highly focused beams and explored the optical response of dielectric-plasmonic crystals. For the first time, his group realized the excitation of sub-wavelength plasmonic gap-waveguides and of plasmonic nano-circuitries via nanoantennas. Modelling activities focus on the efficient implementation of codes simulating light-matter interaction in semiconductor nanostructures based on finite-difference time domain (FDTD) codes coupled with semiconductor Maxwell-Bloch equations.
Ulf Peschel has been working in the field of optics for more than 20 years, both theoretically and experimentally, with a focus on integrated optics, nanophotonics, nonlinear dynamics and electromagnetic modelling. He currently investigates optical fiber systems, where discreteness is realized in the temporal domain, and where gain and loss can be applied in a balanced manner obeying parity-time (PT ) symmetry. In the field of nanophotonics, Prof. Peschel is dealing with epsilon-zero-metamaterials, photonic crystals and plasmonicnano-circuitries driven by nanoantennas.
Prof. Peschel is currently giving lectures on the theoretical concepts of modern optics, including the linear and nonlinear aspects of light-matter interaction.
A computer cluster including respective software and licenses is hosted and maintained in Ulf Peschel's group. The group has vast experience in the numerical solution of various optical problems and uses a lot of standard methods of electromagnetic modeling, including the beam propagation method, finite difference time domain (FDTD) codes and eigenmode solvers. A running fiber loop setup is available for proof-of-principle experiments on linear and nonlinear dynamics in optical systems.