Surface plasmon assisted optical nonlinearities of uniformly oriented metal nano-ellipsoids in glass.

The nonlinear optical properties of nanocomposites consisting of non-spherical silver nanoparticles in glass matrix have been studied using the femtosecond Z-scan technique. The spheroidal nanoparticles were uniformly oriented along a common direction. By polarization sensitive studies, longitudinal and transverse plasmon resonances can be addressed separately.

Directionally selective optical limiting of femtosecond pulses in simple transparent two-layer systems.

Directionally selective nonlinear transmission behavior has been observed for simple glass-based two-layer systems in Z-scan experiments employing femtosecond pulses at a wavelength of λ=800 nm. Glass sheets of 1 mm thickness with a very thin surface layer (~2 μm) containing spherical Ag nanoparticles have been studied. In these samples, irradiating from the substrate side causes a strong transmission decrease via self-focusing of the beam and subsequent two-photon absorption in the thin layer, whereas the reverse direction may pass the sample without loss.

Applanation-free femtosecond laser processing of the cornea.

A novel approach for applanation-free femtosecond refractive surgery with the help of a contact liquid layer is presented. A laboratory device for performing corneal procedures is described based on a femtosecond-laser system which has been tested and evaluated by processing ex vivo pig eyes. With its help, flap cuttings for different flap thicknesses were performed.

Preparing large-aspect-ratio prolate metal nanoparticles in glass by simultaneous femtosecond multicolor irradiation.

By irradiating spherical metal nanoparticles embedded in glass with several hundred ultrashort laser pulses at peak intensities of 0.2-1.5 TWcm(2), dichroic microstructures can be written in these nanocomposite materials.