Raman upshifted third harmonic generation of a laser in a plasma

Journal Article · Mon Nov 15 04:00:00 EST 2010 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3491099· OSTI ID:21531940

Singh, Ranjeet; Tripathi, V K ^[1]

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1. Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016 (India)

The plasma wave produced in a stimulated Raman back scattering process in plasma is seen to be effective in the resonant Raman upshifted third harmonic generation of the same laser or of another laser of a slightly lower frequency. The process requires plasma density slightly lower than the quarter critical density corresponding to the first laser frequency. The electron density perturbation due to the plasma wave beats with the drift velocity imparted by the second harmonic ponderomotive force to produce a density perturbation at Raman upshifted second harmonic. This perturbation couples with the oscillatory electron velocity due to the laser to produce Raman upshifted third harmonic current density and radiation field. The phase matching condition in cold plasma is satisfied when a plasma density is quarter critical. Thermal effects lower the requisite electron density a bit. The energy conversion efficiency from the pump to the Raman upshifted third harmonic could be quite large when the laser intensity exceeds 10{sup 16} W/cm{sup 2}. The plasma inhomogeneity, however, is a significant limiting factor.

• OSTI ID: 21531940
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 11 Vol. 17; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
BACKSCATTERING
CONVERSION
CURRENT DENSITY
DISTURBANCES
EFFICIENCY
ELECTRON DENSITY
ENERGY CONVERSION
FREQUENCY MIXING
HARMONIC GENERATION
LASERS
PLASMA DENSITY
PLASMA WAVES
RAMAN EFFECT
SCATTERING