Frequency Shift Induced in Laser Pulses by Plasma Density Variations.

摘要

An analytical theory is developed which describes how a radiation pulse becomes 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 wavenumber of the radiation pulse. It is shown that temporal variations in the plasma density result in frequency shifts of the radiation. The possibility of up shifting the frequency of the laser pulse using plasma waves is analyzed, and 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. Keywords: Laser plasma interactions; Frequency shifts; Plasma variations. (JHD)