E. M. L. English

Geometry- and diffraction-independent ionization probabilities in intense laser fields : Probing atomic ionization mechanisms with effective intensity matching

We report an experimental technique for the comparison of ionization processes in ultrafast laser pulses irrespective of pulse ellipticity. Multiple ionization of xenon by 50 fs 790 nm, linearly and circularly polarized laser pulses is observed over the intensity range 10 TW/cm{sup 2} to 10 PW/cm{sup 2} using effective intensity matching (EIM), which is coupled with intensity selective scanning (ISS) to recover the geometry-independent probability of ionization. Such measurements, made possible by quantifying diffraction effects in the laser focus, are compared directly to theoretical predictions of multiphoton, tunnel and field ionization, and a remarkable agreement demonstrated. EIM-ISS allows the straightforward quantification of the probability of recollision ionization in a linearly polarized laser pulse. Furthermore, the probability of ionization is discussed in terms of the Keldysh adiabaticity parameter {gamma}, and the influence of the precursor ionic states present in recollision ionization is observed.

Isolated vibrational wavepackets in D 2 + : Defining superposition conditions and wavepacket distinguishability

Tunnel ionization of room-temperature D{sub 2} in an ultrashort (12 femtosecond) near infrared (800 nm) pump laser pulse excites a vibrational wavepacket in the D{sub 2}{sup +} ions; a rotational wavepacket is also excited in residual D{sub 2} molecules. Both wavepacket types are collapsed a variable time later by an ultrashort probe pulse. We isolate the vibrational wavepacket and quantify its evolution dynamics through theoretical comparison. Requirements for quantum computation (initial coherence and quantum state retrieval) are studied using this well-defined (small number of initial states at room temperature, initial wavepacket spatially localized) single-electron molecular prototype by temporally stretching the pump and probe pulses.

Mapping the evolution of optically generated rotational wave packets in a room-temperature ensemble of D2

A coherent superposition of rotational states in

Observing time-dependent vibrational quantum dynamics in deuterium hydride molecular ions

{\mathrm{D}}_{2}

Controlling dissociation processes in the D-2(+) molecular ion using high-intensity, ultrashort laser pulses

has been excited by nonresonant, ultrafast

Dynamic imaging of a dissociative D-2(+) nuclear wavepacket in intense laser fields

(12\phantom{\rule{0.3em}{0ex}}\mathrm{fs})

On the recollision-free excitation of krypton during ultrafast multi-electron tunnel ionization

, intense

Intense-field dissociation dynamics of D+2 molecular ions using ultrafast laser pulses

(2\ifmmode\times\else\texttimes\fi{}{10}^{14}\phantom{\rule{0.3em}{0ex}}\mathrm{W}\phantom{\rule{0.2em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2})

Atomic excitation during recollision-free ultrafast multi-electron tunnel ionization

800\phantom{\rule{0.3em}{0ex}}\mathrm{nm}