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We demonstrate the capabilities of the recently introduced interferometric parallel pulse shaper setup and present a method for fully tailoring the three-dimensional electrical field of femtosecond laser pulses. The possibility of producing parametric polarization pulses with arbitrary orientations and ellipticities in time is demonstrated with a selection of example pulses. OCIS codes: 320.5540, 320.7080, 190.7110.

We present a shaper scheme that fully controls the spectral phase, amplitude, and polarization of femtosecond laser pulses. In particular, it enables independent manipulation over the major axis orientation and the axis ratio of the polarization ellipse. This is accomplished by integrating a 4f-shaper setup in both arms of a Mach-Zehnder interferometer and rotating the polarization by 90[degrees] in one of the arms before overlaying the beams. The generated pulses are resolved in a simple and intuitive detection scheme. OCIS codes: 320.5540, 320.7080, 190.7110.

We present a routine for calculating and producing customized/parametric femtosecond laser pulses for investigating molecular processes involving the polarization. It is applied on the ionization of NaK molecules by feedback-loop optimization using the recently introduced double-pass “serial setup” that is capable of phase, amplitude, and polarization modulation. The temporal subpulse encoding uses the parameters distance, intensity, zero order spectral phase, and polarization state. [ABSTRACT FROM AUTHOR]

Selective optimization of the 39,39K2 and 39,41K2 isotopomers in a three-photon ionization process is presented by applying evolution strategies on shaped fs pulses in a feedback loop. The optimizations at different center wavelengths show considerably large enhancements of one isotope compared to the other and reversed. We compare the acquired optimized pulse shapes for combined phase and amplitude with pure amplitude modulation. Particularly from their spectra we are able to extract information about the optimally chosen differing ionization paths via the involved vibrational states. Furthermore, a comparison of the temporal shape of the optimized pulse forms for combined phase and amplitude with pure phase optimization is given. The presented pulse form analysis demonstrates the potential of restricted optimization to gain insight into the underlying dynamical processes. Our approach reveals how the optimization algorithm precisely addresses the vibrational wave functions both spectrally and temporally.© 2005 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Selective optimization of different isotopomers in an ionization process with shaped fs-laser pulses is presented for 23Na39K/23Na41K. By employing evolution strategies in a closed feedback loop a considerably high enhancement by a total factor of about 25 of one isotope compared to the other and reversed is measured. Surprisingly, vibrational levels of differing electronic states are utilized for the different isotopomer selections. Our approach generally allows to influence vibrational wave functions by coherent interaction with the corresponding spectral pulse components on the fs-time scale. [Copyright &y& Elsevier]