Resonant Excitation of Millimeter Wave by Beating two Lasers in a Plasma Embedded with a Magnetic Wiggler

Two high power lasers of frequencies w$_{1}$ and w$_{2}$, co-propagating in a semiconductor embedded with a magnetic wiggler, produce electromagnetic radiation at the difference frequency (w$_{1 }$-w$_{2})$. The lasers exert a ponder-motive force on the electrons at the difference frequency, giving them longitudinal oscillatory velocity. This velocity beats with the magnetic wiggler to produce a transverse current, driving a millimeter wave at a frequency w$_{1 }$-w$_{2}$ and wave number k$_{1}$-k$_{2}$+k$_{w}$ where k$_{1}$ and k$_{2}$ are the wave number of the lasers and k$_{w}$ is the wave number of the wiggler. For a suitable value of wiggler wave number the process becomes a resonant one, giving high efficiency of millimeter wave generation.