Fig. 1. Photographs of the $3\omega _{0}/2$ harmonic emission from six-beam-irradiated spherical targets taken from two perpendicular directions. (a) 1 $\mathrm {\mu} {\rm m}$ polymer coated target, initial diameter 252 $\mathrm {\mu} {\rm m}$, irradiance $3 \times 10^{13}\ {\rm W}/{\rm cm}^{2}$. (b) 1 $\mathrm {\mu} {\rm m}$ polymer coated target, initial diameter 187 $\mathrm {\mu} {\rm m}$, irradiance $9 \times 10^{13}\ {\rm W}/{\rm cm}^{2}$^[10].

Fig. 2. $(3/2)\omega _{0}$ time and space resolved photographs, along the filament channels. (a) The experimental setup. The magnification of the imaging optics was 19, with the temporal resolution of 5–10 ps and the spatial resolution of 5 $\mathrm {\mu} {\rm m}$. (b) Shot No. 107; narrow band laser irradiation on a Ta plain target with laser incidence angle $\sim 10^{\circ }$, energy 8.3 J and pulse width 250 ps. (c) Shot No. 124; narrow band laser irradiation on an Al plain target with laser incidence angle $\sim 20^{\circ }$, energy 8.1 J and pulse width 250 ps. (d) Shot No. 113; broad band laser irradiation on a Ta target with laser incidence angle $\sim 10^{\circ }$, energy 3.6 J and pulse width 250 ps ^[15].

Fig. 3. Experimental arrangement for space and time resolved spectroscopy of the $(3\omega _{0}/2)$ emission^[12].

Fig. 4. The $3\omega _{0}/2$ spatially resolved spectrum^[13].

Fig. 5. The temporally resolved spectrum^[12].

Fig. 6. (a) Shadowgraph recorded on a glass target 1 ns after the beginning of the laser pulse, showing pronounced plasma jets with the clear filament node modulation. (b) Laser beam profile taken in the equivalent target plane. (c) X-ray pinhole camera image in the 1.5 keV energy band (pinhole filtered with 40 $\mathrm {\mu} {\rm m}$ of beryllium). The scale for all the images is 50 $\mathrm {\mu} {\rm m}$, for (a), (b), and (c). (d) Shadowgraph 1.4 ns delayed from the beginning of the laser pulse, showing pronounced plasma jets without filament node modulation. (e) Temporal profile of the green heating laser pulse^[11].

Fig. 7. (a) SBS time resolved spectrum with an unsmoothed beam. (b) SBS time resolved spectrum with an RPP smoothed beam. (c) SRS time resolved spectrum with an unsmoothed beam. (d) SRS time resolved spectrum with an RPP smoothed beam^[17].

Fig. 8. Small scale self-focusing filaments in the rod amplifier^[25].

Fig. 9. Two samples of focal spot intensity distribution are given with different spatial smoothing mechanisms. (a) The measured focal spot and profiles along two dimensions of SG-II laser facility from a CCD (charge coupled device) of $1024\times 1024$ elements with each pixel size being 13 $\mathrm {\mu} {\rm m}$ at ${\sim }12\times $ magnification when a lens array is applied to the laser beam, and the measured speckle contrast is 0.46 rms. (b) The measured (top) and calculated (below) far-field speckle profile on NIF when CPP is applied to the laser beam, and the measured contrast is 0.79 rms^{[26, 27]}.

Fig. 10. The laser produced a very smooth and flat shock front yielded by a seriously fluctuating irradiance of less than around $5 \times 10^{13}\ {\rm W}/{\rm cm}^{2}$, and a rather low laser power intensity on the target surface. (a) Rear shock luminescence signal images of a 30 $\mathrm {\mu} {\rm m}$ Al planar target measured using the optical streak camera. The measured scope size on the planar target is about 800 $\mathrm {\mu} {\rm m}$, and the time fluctuation of the laser produced shock front is 3.83 ps (rms) with a good planarity, compared to the time of 1.5 ns when a shock wave is transmitting in the target. (b) Four-step Al target experiments with the Al substrate thickness of 20 $\mathrm {\mu} {\rm m}$: experimental results with the average shock velocity of 20.9 km s$^{-1}$, with the velocity contrast at less than 0.5% and the linear correlation coefficient of 0.999,96. The two results show that planarity of the shock wave can still be maintained although there are many intensity modulations in the focal spot^[28].