Observation of a long-wavelength hosing modulation of a high-intensity laser pulse in underdense plasma.
We report the first experimental observation of a long-wavelength hosing modulation of a high-intensity laser pulse. Side-view images of the scattered optical radiation at the fundamental wavelength of the laser reveal a transverse oscillation of the laser pulse during its propagation through underdense plasma. The wavelength of the oscillation λ(hosing) depends on the background plasma density n(e) and scales as λ(hosing)∼n(e)(-3/2). Comparisons with an analytical model and two-dimensional particle-in-cell simulations reveal that this laser hosing can be induced by a spatiotemporal asymmetry of the intensity distribution in the laser focus which can be caused by a misalignment of the parabolic focusing mirror or of the diffraction gratings in the pulse compressor.
Kaluza
M C
MC
The Blackett Laboratory, Imperial College London, London SW7 2BZ, United Kingdom.
Mangles
S P D
SP
Thomas
A G R
AG
Najmudin
Z
Z
Dangor
A E
AE
Murphy
C D
CD
Collier
J L
JL
Divall
E J
EJ
Foster
P S
PS
Hooker
C J
CJ
Langley
A J
AJ
Smith
J
J
Krushelnick
K
K