Spatial anisotropy of the velocity of electrons emitted from a short-pulse laser focus

Saeed, M.; Dyer, Mark J.; Helm, H.

doi:10.1103/physreva.49.1491

Cited by 8 publications

(5 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Following the results of Ref. [16], we estimate the acceleration energy to be less than 1 meV over the entire energy spectrum, which is much less than the EIS resolution. Using Eq.…”

mentioning

confidence: 76%

Photodetachment ofH−in a Strong Infrared Laser Field

2001

Self Cite

View full text Add to dashboard Cite

Negative hydrogen ions are exposed to a short infrared laser pulse of 2.15 microm wavelength and 250 fs duration. An imaging technique is used to record the energy resolved angular distribution of photoelectrons. The energy spectrum reveals at least three excess photon detachment channels. A quantum interference effect, resulting in an unusual dependence of the angular distribution on the electron kinetic energy, is most prominent in the lowest two-photon detachment channel. The appearance of this effect is discussed in terms of the threshold law of photodetachment.

show abstract

“…Following the results of Ref. [16], we estimate the acceleration energy to be less than 1 meV over the entire energy spectrum, which is much less than the EIS resolution. Using Eq.…”

mentioning

confidence: 76%

Photodetachment ofH−in a Strong Infrared Laser Field

2001

Self Cite

View full text Add to dashboard Cite

show abstract

“…Assuming a sech profile, the pulse widths lie typically between 600 and 900 fs, varying with wavelength. Hence, under our experimental conditions, photoelectrons with energies in the range from zero to above 10 eV recover only a negligible amount of the ponderomotive shift of the ionization limit due to acceleration by the ponderomotive potential [9,10]. Thus the photoelectrons appear with energies corresponding to the energy they possess at creation.…”

Section: Introductionmentioning

confidence: 92%

Resonant and nonresonant multiphoton ionization of helium

Helm

Dyer

1994

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

We have investigated the multiphoton ionization of helium at wavelengths between 310 and 330 nm at intensities between 8X10' and 5X10' W/cm and at 630 nm at intensities of 1X10' W/cm . We characterize the ionization processes from photoelectron energy and angular distributions observed concurrently with photoion spectra. At the shorter wavelengths we find that resonant enhancement via the ac Stark shifted six-photon resonant states (1s3d and 1s3s) is a dominant ionization path as described previously by Perry, Szoke, and Kulander [Phys. Rev. Lett. 63, 1058 (1989)] and by Rudolph et al. [Phys. Rev. Lett. 66, 3241 (1991)]. At intensities above those required for resonant enhancement, and at wavelengths longer than those required for six-photon resonance, we observe that nonresonant sevenphoton ionization dominates. This process gives rise to continuous distributions of low-energy electrons with characteristic angular distributions that peak near 0 and 60' relative to the laser polarization. At yet higher intensities, above the threshold where the nonresonant seven-photon channel closes, the dominant ionization path occurs via seven-photon resonant states with odd parity. This path gives rise to angu1ar distributions characteristic of intermediate states with f character.

show abstract

“…As in our previous experiments [6], the difficulty of exposing negative ions to high laser intensities is overcome by using an infrared laser pulse of 100 fs duration. In such a short pulse the electron acceleration due to the gradient of the intensity distribution in the laser focus can be neglected [13]. The experimental apparatus is basically the same as used before [14].…”

mentioning

confidence: 99%

Experimental Study of Photodetachment in a Strong Laser Field of Circular Polarization

Bergues

Helm

et al. 2005

Phys. Rev. Lett.

Self Cite

View full text Add to dashboard Cite

Negative fluorine ions are exposed to a circularly polarized infrared laser pulse with a peak intensity on the order of 2.6 x 10(13) W/cm(2). A fundamental difference, as compared to the case of linearly polarized field, is found in the absence of any structure in the photoelectron spectrum that can be associated with the quantum interference effect. This observation is in accord with our recent predictions [S. Beiser, Phys. Rev. A 70, 011402 (2004)10.1103/Phys. Rev. A.70. 011402]. The experiment reveals that the length gauge is appropriate for the description of the field interaction in the frame of the strong field approximation.

show abstract

Spatial anisotropy of the velocity of electrons emitted from a short-pulse laser focus

Cited by 8 publications

References 10 publications

Photodetachment ofH−in a Strong Infrared Laser Field

Photodetachment ofH−in a Strong Infrared Laser Field

Resonant and nonresonant multiphoton ionization of helium

Experimental Study of Photodetachment in a Strong Laser Field of Circular Polarization

Contact Info

Product

Resources

About