Simultaneous spatio-temporal focusing with pulse front symmetrization.

Simultaneous spatio-temporal focusing of ultrashort pulses is usually performed by single-channel stretcher-compressor geometries where pulse front tilt leads to spatial asymmetry. Here, the basic approach is extended by superimposing two reciprocal sub-beams in a dual-channel stretcher-compressor setup. Spatio-temporal properties of the symmetrized focal zones of few-cycle near-infrared pulses are studied by parametric numerical simulations with physical optics software.

Self-imaging of tailored vortex pulse arrays and spectral Gouy rotation echoes.

Self-imaging of femtosecond pulses with orbital angular momentum is studied in spectral domain by illuminating the orthogonal arrays of spiral gratings. Spectral Gouy rotation, i.e.

Nondiffracting self-imaging of ultrashort wavepackets.

Self-imaging of ultrashort-pulsed nondiffracting needle beams, i.e., fringe-free Bessel beams, is analyzed.

Sub-3-cycle vortex pulses of tunable topological charge.

Novel types of reflective spiral micro-electro-mechanical systems were used to generate few-cycle vortex pulses of variable topological charge from a Ti:sapphire laser oscillator. The phase profile of these components was controlled by varying the temperature. The temporal properties of the pulses were characterized with spatially resolved nonlinear autocorrelation.