LAUSR

Electrostatic modes present in laser produced plasma are capable of generating strong harmonic radiation. Electrostatic waves provide phase matching and contribute to non-linear coupling. In this paper, lower hybrid waves assist in k-matching to produce the third harmonic of the laser. As the frequency of the lower hybrid wave is very small, the harmonic produced is close to exact. At normalized parameters (amplitude, density, and plasma length), the normalized amplitude of the third harmonic is quite high at a particular value of ω0/ωp and ωc/ωp. This occurs in the proximity of upper hybrid resonance as the process becomes resonant for this value. The magnitude of the normalized amplitude increases as ω02 is close to ωUH2.