Fig. 1. (a)–(d) Normalized absolute amplitude of the vector potential on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c for beams 1 [(a) and (c)] and 2 [(b) and (d)] in cases I [(a) and (b)] and II [(c) and (d)]. (e) and (f) Normalized absolute amplitude of the vector potential on a slice in the ŷ–ẑ plane at x = 185λ_c for beam 2 in cases I and II, respectively.

Fig. 2. (a) and (b) FOPAI of beams 1 and 2, respectively, diagnosed in the outgoing x̂–ŷ plane in the different cases listed in Table I. Solid and dashed lines denote the polarization components in the x and y directions, respectively.

Fig. 3. Real and imaginary parts (orange and blue lines, respectively) of the plasma coupling coefficient K vs the wavelength separation between two beams when the plasma flow velocity is zero.

Fig. 4. Normalized absolute amplitude of the x [(a) and (b)] and y [(c) and (d)] polarization components of the vector potential on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c for beams 1 [(a) and (c)] and 2 [(b) and (d)] in case III.

Fig. 5. Normalized absolute amplitude of the x [(a) and (b)] and y [(c) and (d)] polarization components of the vector potential on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c for beams 1 [(a) and (c)] and 2 [(b) and (d)] in case IV.

Fig. 6. (a) Normalized absolute amplitude of the vector potential on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c for scattered light from SBS in case II. (b) Normalized absolute amplitude of the density perturbation on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c corresponding to the ion-acoustic wave stimulated by beam 2 in case II.

Fig. 7. Normalized absolute amplitude of the vector potential on different slices in the x̂–ŷ plane at z = 0λ_c, 170λ_c, 340λ_c, and 512λ_c for (a) beam 1, (b) beam 2, (c) beam 3, and (d) beam 4 in the case of four overlapping beams.

Fig. 8. FOPAI of beams 1 and 2 (solid and dashed lines, respectively) diagnosed in the outgoing x̂–ŷ plane. The red curves are for case II of two beams and the black curves for the case of four overlapping beams.

Table 1. Simulations of propagation of two overlapping beams.