ABSTRACT: We present an analytical method for generating ultra-fast pulse sequences. In this approach, the physically intuitive parameters
of the sub-pulses—energy, position in time, relative phase, chirp, and the polarization state—can be controlled individually.
The pulses are experimentally generated by a pulse shaper which has been recently introduced. It uses three commercial double
liquid crystal array modulators to mimic the optimal setup which utilizes four liquid crystal arrays for modulation. A series
of double pulses systematically demonstrates the separate and independent control of the sub-pulse parameters. Furthermore,
complex multi-pulse sequences are shown.
Applied Physics B 04/2012; 101(1):79-91. · 2.19 Impact Factor
ABSTRACT: We present spectrally resolved pump-probe experiments on the photoassociation of ultracold rubidium atoms with shaped ultrashort
laser pulses. The pump pulse causes a free-bound transition leading to a coherent transient signal of rubidium molecules in
the first excited state. In order to achieve a high frequency resolution the bandwidth of the pump pulse is reduced to a few
wavenumbers. The frequency dependence of the transient signal close to the D1 atomic resonance is investigated for characteristic
pump-probe delay times. The observed spectra, which show a pronounced dip for pump-probe coincidence, are interpreted using
quantum dynamical calculations.
The European Physical Journal D 04/2012; 54(3):711-714. · 1.48 Impact Factor
ABSTRACT: We demonstrate the photoassociation of ultracold rubidium dimers using coherent femtosecond pulses. Starting from a cloud of ultracold rubidium atoms, electronically excited rubidium molecules are formed with shaped photoassociation pump pulses. The excited state molecules are projected with a time-delayed probe pulse onto molecular ion states which are detected in a mass spectrometer. Coherent transient oscillations of the excited state population are observed in the wings of the pump pulse, in agreement with the time-dependent solution of the Schrödinger equation of the excitation process.
Physical Review Letters 06/2008; 100(23):233003. · 7.37 Impact Factor
Chemical Physics 01/2007; 332:313. · 1.90 Impact Factor
Physical Review A 01/2007; 76:063404. · 2.88 Impact Factor
ABSTRACT: We introduce a shaper setup which takes advantage of laser pulses passing through a spatial light modulator twice, thereby
effectively utilizing a four-liquid crystal mask configuration. This approach grants control not only over the phase and polarization
but also the amplitude. The Jones vector of the light wave after passing through the setup is considered in detail including
polarization sensitive grating efficiency. A new method of counteracting the polarization dependent grating transmission is
described and a comparison between the desired and recorded pulses is presented.
Applied Physics B 12/2006; 86(2):259-263. · 2.19 Impact Factor