Two counter-propagating lasers, with frequencies omega(1),omega(2), and wave numbers k(1),k(2) drive, in an underdense plasma of plasma frequency omega(p), a nonresonant space charge wave at frequency difference omega(0)greater than or equal to2omega(p) and wave number k(0)approximate tok(1)+k(2). The driven wave undergoes stimulated Raman scattering producing a plasma wave and a scattered electromagnetic sideband wave (omega(s),k(s)). The growth rate of the process, gamma, is comparable to two plasmon decay and maximizes for side scattering at theta(s)=pi/2, i.e., when (k) over right arrow (s)perpendicular to(k) over right arrow (0). (C) 2004 American Institute of Physics.