Resonant laser beat wave THz generation in a plasma channel

Phase matched terahertz (THz) generation by non-linear mixing of two lasers in a plasma channel is investigated. An electrostatic wave mediates in the nonlinear process and provides phase matching. The TM mode lasers impart a beat frequency ponderomotive force on electrons, giving them an oscillating velocity. The nonlinear velocity beats with the density perturbation, associated with the electrostatic wave, to produce a non-linear current, driving TM mode THz radiation. The nonlocal effects reduce the power conversion efficiency. (author)