Stimulated compton scattering of surface plasma wave excited over metallic surface by a laser

Abstract

AbstractA high-frequency surface plasma wave (SPW) excited over metallic surface irradiated by a laser beam, can undergo stimulated Compton scattering if phase velocity of daughter plasma wave is equal to the Fermi velocity for metal. The pump SPW${\rm (}{{\rm \omega} _0},{\vec k_{0{\rm z}}})$parametrically excites a quasi-electrostatic plasma wave${\rm (\omega}, {\vec k_{\rm z}})$and a backscattered sideband SPW${\rm (}{{\rm \omega} _1},{\vec k_{1{\rm z}}})$at resonance ω0= ω − ω1and${\vec k_{0{\rm z}}} = {\vec k_{\rm z}} - {\vec k_{1{\rm z}}}$. The growth rate of Compton process increases with the frequency of incident laser and turns out to be 5.425 × 1010rad/s at laser frequency ω0= 0.7595 × 1015rad/s for incident laser amplitudeA0L= 11 × 1011V/m, laser spot size b = 1.38 × 10−5m, and free electron density of metaln0= 5.85 × 1028/m3. The excitation of highly damped quasi-electrostatic plasma wave in this parametric process provide a better nonlinear option for surface heating as compared with direct laser heating. The process can also be used for diagnostics purposes.