Hannover 2010 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 13: Ultrashort Laser Pulses: Generation II
Q 13.8: Vortrag
Montag, 8. März 2010, 18:15–18:30, F 342
Sub-20 fs pulse shaping in the UV by an acousto-optical programmable dispersive filter (AOPDF) — •Rafael Probst, Nils Krebs, and Eberhard Riedle — Lehrstuhl für BioMolekulare Optik, LMU München
Ultrashort laser pulses of controlled complex pulse shape are of high interest in innovative fields of research like coherent control of molecular dynamics and 2D spectroscopy. Until recently, direct shaping of femtosecond light pulses was restricted to the visible and IR regime. We apply a newly available very compact (8 x 8 x 4 cm3) acousto-optic pulse shaper (DazzlerTM) that offers full control over the spectral amplitude and phase at wavelengths deep into the UV (240 - 420 nm). The primary broadband UV pulses are generated by frequency doubling of a NOPA. We characterize the shaped pulses by ZAP-SPIDER, X-FROG and difference frequency cross correlation with visible 13 fs pulses. We demonstrate that intrinsic problems of spatial chirp can be solved through a specially designed optical beam path that properly takes into account aspects of geometric as well as Gaussian optics. This allows us to generate nearly transform limited pulses as short as 16.8 fs at 320 nm and 19.5 fs at 260 nm. Within a temporal shaping window of up to 3 ps we demonstrate full control over the amplitude and phase of the pulses by generating arbitrary pulse shapes, e.g., square pulses and complex pulse sequences. The subpulses were manipulated individually in intensity, temporal delay, chirp, relative phase and central wavelength, demonstrating the remarkable possibilities of the setup.