Fig. 1. (a) Schematic of stimulated Raman side scattering (SRSS) and its rescattering in an inhomogeneous plasma. (b) Wave vector matching condition of first-order SRSS. (c) Wave vector matching condition of second-order rescattering of SRSS.

Fig. 2. (a) Spectrum of E_z(x, k_y) in x–k_y space averaged over 2 ps. The red dashed vertical line indicates a density n_e = 0.11n_c. (b) The corresponding spectrum E_z(k_x, k_y) in wave vector (k_x–k_y) space. (c) Spectrum of EPWs E_x(k_x, k_y) overlaid with wave vector matching conditions. (d) Blow-up of the region outlined by the red dashed rectangle in (c). These are Fourier spectra of real quantities, and so they are symmetric in k.

Fig. 3. Frequency–wave vector spectrum of light waves E_z(k_y, ω) at n_e = 0.09n_c over the interval t = [1.4 ps, 1.5 ps].

Fig. 4. Growth of scattered light amplitudes over time. The red, green, and blue dots are the relative scattered light amplitudes E of first SRSS at n = 0.09n_c, n = 0.12n_c, and n = 0.15n_c, respectively. The red plus signs are the relative scattered light amplitudes E of second SRSS at n = 0.09n_c.

Fig. 5. (a) and (b) Electron distribution functions in momentum space at t = 1 and 2 ps, respectively. The red and yellow arrows indicate the EPW directions of the first- and second-order SRSS, respectively. (c) and (d) Electron distribution functions in x–p_x phase space at the corresponding times. (e) and (f) Electron distribution functions in x–p_y phase space at the corresponding times.

Fig. 6. Evolution of energy spectra along the propagation directions of the first- and second-order EPWs.

Fig. 7. (a)–(d) E_z(x, k_y) averaged over 2 ps for pump intensities I = 1 × 10¹⁴ W/cm², 5 × 10¹⁴ W/cm², 1 × 10¹⁵ W/cm², and 1 × 10¹⁶ W/cm², respectively. The density scale length at 0.2n_c is L = 400 μm and the electron temperature is T_e = 2 keV.

Fig. 8. (a)–(d) E_z(x, k_y) averaged over 2 ps for density scale lengths at 0.2n_c of L = 100, 200, 400, and 800 μm, respectively. The pump intensity is I = 1 × 10¹⁵ W/cm² and the electron temperature is T_e = 2 keV.

Fig. 9. (a)–(d) E_z(x, k_y) averaged over 2 ps for electron temperatures T_e = 1, 2, 5, and 10 keV, respectively. The pump intensity is I = 1 × 10¹⁵ W/cm² and the density scale length at 0.2n_c is L = 400 μm.