Light and Matter

Research in the program Light and Matter will proceed in four areas: investigations of optical and dynamic properties of liquid crystals and related soft matter systems, including the properties of composite systems and complex geometries; research of new materials with strong nonlinear optical response; investigations of laser materials and systems; use of lasers and optical methods in medicine. In all these areas similar and partly overlapping methods and instrumentation will be used. Dynamic light scattering with photon correlation technique will be used to study fluctuation properties of different liquid crystal systems, with emphasis on the role of interactions between liquid crystals and surfaces, and viscoelastic properties and their connection with microscopic models in ferroelectric and antiferroelectric liquid crystal phases. Defect structures in liquid crystals will be investigated with optical methods. The study of slow fluctuations and optical properties will be extended to other soft matter systems, for example to structures polyelectrolyte solutions and biological membranes. In polar spatially modulated liquid crystal phases we will investigate nonlinear optical processes like second harmonic generation and parametric amplification in the vicinity of spatial resonances due to the modulation. Time resolved optical spectroscopy will be used to study molecular dynamics in liquid crystals and similar materials on picosecond time-scale. In new crystal materials we will measure optical absorption, photoconduction, and photorefractive response, especially in the near infrared region. The aim is to find a material with a photorefractive response in the infrared that will be comparable with the existing materials in the blue-green region of the spectrum. Optical phase conjugation due to thermal and stimulated Brillouin scattering will also be investigated. In the field of laser physics and materials we will try to develop efficient and simple spectroscopic and optical methods to characterize laser system components. We will develop realistic and efficient computational models to study the behavior of lasers. In collaboration with medical specialists we will investigate the effects of strong laser light pulses on different tissues, at first primarily on dental tissues and skin. These results will be used to develop new lasers sources, specifically tailored for medical use.