Two-Plasmon Decay and Three-Halves Harmonic Generation in Filaments in a Laser-Produced Plasma

The two-plasmon decay of light propagating in filaments in a laser-produced plasma and the resulting $\frac{3{\omega }_0}{2}$ light emission is discussed with use of a simplified model. Experimental observations are consistent with the predictions of the model. Implications for use of the $\frac{3{\omega }_0}{2}$ doublet splitting as a temperature diagnostic are discussed.