Time-Resolved Observations of the Three-Halves Harmonic Spectrum from Laser-Produced Plasmas

Time-resolved $\frac{3}{2}{\omega }_0$ spectra from glass microballoons irradiated by 100-ps, 2×${10}^{16}$-${\mathrm{W}}_{\mathrm{o}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ laser pulses have been obtained with a temporal resolution of 20 ps and a spectral resolution of 15 Å. Pulsed emission is observed, with a pulse duration of less than the instrument limit. Both red and blue peaks appear simultaneously, with their separation varying in time.