Attosecond pulses generated by the lighthouse effect in Ar gas
Abstract
We numerically investigate harmonic generation in Ar gas under high ionization conditions and demonstrate that a lighthouse effect is present. We examine the structure of the driving field during propagation in temporal, spectral, and spatial domains, and conclude that the complete depletion of neutral Ar on axis gives rise to additional wavelets at off-axis regions. We show that these wavelets propagate with increasing divergence as the radial distances from the axis increase, generating the rotation of the wave front, thus fulfilling a necessary condition for the lighthouse effect. We obtain attosecond bursts of light emitted with different divergences in successive optical half-cycles so that in the far field these bursts arrive at different distances from the beam axis.
- Publication:
-
Physical Review A
- Pub Date:
- May 2015
- DOI:
- 10.1103/PhysRevA.91.051801
- Bibcode:
- 2015PhRvA..91e1801T
- Keywords:
-
- 42.65.Ky;
- 32.80.Wr;
- 42.65.Re;
- 42.65.Jx;
- Frequency conversion;
- harmonic generation including higher-order harmonic generation;
- Other multiphoton processes;
- Ultrafast processes;
- optical pulse generation and pulse compression;
- Beam trapping self-focusing and defocusing;
- self-phase modulation