Stimulated forward Raman scattering of a laser in a magnetized plasma

A Gaussian laser beam propagating through a low-density plasma in the presence of an azimuthal magnetic field undergoes stimulated forward Raman scattering producing a lower hybrid wave and two radially localized electromagnetic sideband waves. The radial widths of the sidebands are of the order of the spot size of the pump, whereas the radial width of the lower hybrid wave depends on the growth rate of the Raman process. The nonlocal effect arising, due to the azimuthal magnetic field, reduces the region of nonlocal interaction and hence the growth rate. The growth rate of stimulated Raman forward scattering first increases on increasing magnetic field, maximizes at some optimum value of magnetic field, and then decreases. (c) 2007 American Institute of Physics.