Figure 1

Upper frames: Reflectivity (left), showing sub-ps bursts from a simulation in a domain $500\times 80\mu \mathrm{m}$ at $I_{\mathrm{ave}}=2.9\times {10}^{14}\mathrm{W}/{\mathrm{cm}}^2$ with the pump field $E_y$ (right); the black arrow indicates the first SRS burst from strong speckles in the while oval; $R_{\mathrm{SRS}}>1$ bursts are indicated by the red arrows. Middle and lower frames: Snapshots of quantity $\max (-E_y{B}_z,0)$, proportional to the backscatter Poynting flux, showing spatial locations of SRS bursts. Middle left inset: time-averaged (over simulation duration 13.36 ps) electron velocity space distribution measured at the location of the strong speckles (spatially averaged over $\sim {\lambda }_{\mathrm{EPW}}$), showing a strong trapping tail. Middle right inset: The $E_y(x,z)$ field containing both laser and scattered-light wave fronts distinguished by their different wavelengths (as labeled). SRS backscatter light-wave bowing occurring in multiple speckles with two strong speckles centered around $z=14$ and $23\mu \mathrm{m}$. Lower right inset: Time-averaged (over $\sim 13\mathrm{ps}$) SRS spectral power as a function of transverse wave number $k_z{\lambda }_D$, measured at the laser entrance.Reuse & Permissions

Figure 2

Top: Time-averaged SRS reflectivity vs laser average intensity for collections of speckles in domains $500\times 20\mu \mathrm{m}$ [black diamonds; using 512 (65) particles per cell for the four lower intensity runs (at higher intensity)] and $500\times 160\mu \mathrm{m}$ [black triangles; using 512 (65) particles per cell for the two lower intensity runs (at higher intensity)] using density $n_e/n_{\mathrm{cr}}=0.12$ and $T_e=2.6\mathrm{keV}$ ($k{\lambda }_D=0.31$). Middle: Instantaneous reflectivity for $500\times 160\mu \mathrm{m}$ (black) and $1500\times 160\mu \mathrm{m}$ (red) simulations at $I_{\mathrm{ave}}=1.2\times {10}^{14}\mathrm{W}/{\mathrm{cm}}^2$. Lower: Instantaneous reflectivity for the $500\times 160\mu \mathrm{m}$ simulation at $I_{\mathrm{ave}}=2.9\times {10}^{14}\mathrm{W}/{\mathrm{cm}}^2$.Reuse & Permissions