Filamentation effects and second-harmonic spectra in laser-produced plasmas
- MDRTE, Centre de Developpement des Technologies Avancees 2, boulevard Frantz Fanon, Alger-gare, Boite Postale 1017, Alger 16000 (Algeria)
Sideway scattered second-harmonic spectra emitted from a 1064-nm-laser-produced plasma have been observed to originate from nonlinear coupling near the critical surface. The time evolution of the second-harmonic optical density confirmed the possibility that a plasmon issued from the resonant absorption of the incident beam can recombine with a photon ([omega][sub 0]) to give a transverse wave of frequency 2[omega][sub 0]. A plasmon issued from a parametric decay instability may also, by coalescence with an incident photon, give a transverse wave at a shifted second-harmonic frequency. The threshold of such a combination is determined. Moreover, irregular plasma-parameter variations and the perturbed spatial uniformity of the incident beam appear to alter the second-harmonic spectra. An oscillatory structure of the optical density of the observed second harmonic is interpreted as a result of the coupling physics involved and of laser-beam filamentation.
- OSTI ID:
- 6272820
- Journal Information:
- Physical Review. E, Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics; (United States), Vol. 48:2; ISSN 1063-651X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Surface plasmon excitation at second harmonic over a rippled surface
Brillouin shifted third harmonic generation of a laser in a plasma
Related Subjects
LASER-PRODUCED PLASMA
NONLINEAR PROBLEMS
DATA ANALYSIS
EMISSION SPECTRA
NONLINEAR OPTICS
OPACITY
PLASMA DIAGNOSTICS
PLASMONS
RESONANCE ABSORPTION
ABSORPTION
OPTICAL PROPERTIES
OPTICS
PHYSICAL PROPERTIES
PLASMA
QUASI PARTICLES
SORPTION
SPECTRA
700350* - Plasma Production
Heating
Current Drive
& Interactions- (1992-)
700320 - Plasma Diagnostic Techniques & Instrumentation- (1992-)