Nonlinear Optics
Extremely important applications of Nonlinear Science are made in
nonlinear optics. Thus propagation and spatial evolution of light
beams in nonlinear media is a central area. Exact 1+1 dimensional
solitary wave solutions to the nonlinear Schrödinger equation
were found more than 20 years ago. Such solitons will play an
important role in the next generation of optical communication systems
which will operate in the 100 Gbits/sec and higher regimes. At the
moment such bit transmission rates can be obtained in purely optical
systems, whereas electronic detectors and converters constitute
an unsolved technological problem.
There is a growing interest in solitonlike structures in 2 and 3
spatial dimensions. These are generally unstable and may undergo
catastrophic collapse in finite time.
Combined theoretical, numerical, and experimental studies include:
- Creation of ultra-short pulses by nonlinear localization
- Robustness of
solitons with stochastic phase matching in optical materials
with quadratic and cubic and nonlinearities
- Conversion of optical data flow into electronic data using
Josephson arrays
- Self-focussing and collapse of light beams in media with
isotropic, anisotropic and long-range dispersive properties
- Development, characterization, modelling and fabrication of
new optical materials for applications in optical measurement
systems
- Optical storage in nonlinear organic materials
- Intensity dependent phase-modulation, formation of patterns
and dynamics of spatial solitons and optical vortices
(dark spots) in organic materials (e. g. bacteriorhodopsin)
and inorganic materials (e. g. photorefractive crystals)
- Parametric wave couplings and amplification in nonlinear
photorefractive materials
- Mathematical modelling of switching devices, semiconductor
lasers, quantum well lasers and distributed feed back lasers
- Nanostructures and quantum optical effects
The research is carried out in collaboration with The Microelectronic
Center which has contacts with Danish industry.