Not-so-resonant, resonant absorption

When an intense electromagnetic wave is incident obliquely on a sharply bounded overdense plasma, strong energy absorption can be accounted for by the electrons that are dragged into the vacuum and sent back into the plasma with velocities v\ensuremath{\simeq}{v}_{\mathrm{osc}} This mechanism is more efficient than usual resonant absorption for {v}_{\mathrm{osc}/\mathrm{\ensuremath{\omega}}>\mathrm{L}} with L being the density gradient...