The generation of ultrashort laser pulses down to few optical cycles
in a very broad spectral region (from 100 nm up to the THz range)
by nonlinear optical processes is a goal of most of the ongoing
activities within the framework of this project. Besides the further
improvement of known techniques for pulse shortening we also pursue
several new strategies. In this context various nonlinear processes
are studied in microstructure materials and microstructure fibers,
such as supercontinuum generation and superfocusing.
Chirped Photonic Crystal Fibre (CPCF) for
sub-20fs pulse delivery
a) Autocorrelation of a 13-fs pulse from a Ti:sapphire laser.
b) The same after propagation through 1.05 m of
CPCF with 53-µm core size.
c) Autocorrelation for a 1.05-m-long piece of commercial HC800 fibre[SIB08]
In order to either generate new wavelengths or enhance the conversion
efficiency, stability, spectral and spatial quality, and to simplify
already existing concepts we investigate new solid-state nonlinear
optical materials with 2nd and 3rd order nonlinear
susceptibility and apply them in novel interaction schemes for frequency
conversion of femtosecond pulses, e.g. chirped pulse optical parametric
amplification (CPOPA). For tunable and efficient generation of sub-100
fs pulses in the wavelength range 100-160 nm we investigate, both
experimentally and theoretically, four-wave-mixing in special hollow
waveguides and compression of vacuum UV pulses by Raman-active molecular
Simultaneously with these activities devoted to the generation
of ultrashort pulses with one or more extreme parameters we concentrate
on the characterization of their temporal and spatial structure
as well as on active control by shaping mechanisms. The full control
over all parameters of ultrashort and few cycle light pulses (wavelength,
temporal shape, phase, energy, etc.) is a long term objective for
the whole project.
liquid crystal on silicon (LCOS) spatial light modulator
(SLM) for high fidelity temporal pulse transfer .[BGD08]