Frequency shifts induced in laser pulses by plasma waves

Journal Article · Sat Sep 15 04:00:00 EDT 1990 · Physical Review, A (General Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevA.42.3526· OSTI ID:6417919

Esarey, E; Ting, A; Sprangle, P ^[1]

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1. Beam Physics Branch, Plasma Physics Division, Naval Research Laboratory, Washington, DC (USA)

An analytical theory is developed that describes how a radiation pulse is modified as it propagates through a plasma with arbitrary temporal and spatial density variations. Expressions are derived for the shifts induced in both the frequency and the wave number of the radiation pulse. The possibility of upshifting the frequency of the laser pulse using plasma waves is analyzed. It is found that maximum shifts occur when the phase velocity of the plasma wave is equal to the group velocity of the laser pulse. Nonlinear analysis of laser propagation in underdense plasmas ({omega}{sub {ital p}}{sup 2}/{omega}{sup 2}{much lt}1, where {omega}{sub {ital p}} is the plasma frequency and {omega} is the laser frequency) shows that the frequency shift scales asymptotically as the square root of the propagation distance. Furthermore, it is shown that the laser power remains constant as the pulse propagates through the plasma.

• OSTI ID: 6417919
• Journal Information: Physical Review, A (General Physics); (USA), Journal Name: Physical Review, A (General Physics); (USA) Vol. 42:6; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
AMPLIFICATION
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
GAIN
LASER RADIATION
PHASE VELOCITY
PLASMA
PLASMA WAVES
RADIATIONS
SCALING LAWS
SPECTRAL SHIFT
VELOCITY