Cold-plasma left-handed wave ($n^2=L=S+g$)

With the same conventions as the cold-plasma right-handed wave, this transverse electromagnetic wave has $E_y=-i{E}_x$ and refractive index $n^2=S+g$. With immobile ions, $L=1-{\omega }_{pe}^2/[\omega (\omega +{\Omega }_e)]$.