Fig. 1. Amplitude thresholds for the development of eigenmode and non-eigenmode SRS in plasma above the quarter critical density. The threshold for the case of eigenmode SRS is due to the relativistic effect.

Fig. 2. Numerical solutions of SRS dispersion equation at plasma density with laser amplitude . (a) The relativistic modification on the non-eigenmode SRS at . (b) The effect of electron temperature on non-eigenmode SRS. The dotted line and dashed line are the imaginary part and the real part of the solutions, respectively.

Fig. 3. Distributions of the electrostatic wave in space obtained for the time window at plasma density under (a) pump laser amplitude and (b) pump laser amplitude . (c) Distribution of the electromagnetic wave in space obtained under the same conditions as in (b). (d) Longitudinal phase space distribution of electrons under different laser amplitudes at .

Fig. 4. The plasma density is for (a)–(d). (a) Distribution of the electrostatic wave in space obtained for the time window and transverse region . (b) Spatial distribution of electrostatic wave at . (c) Spatial distribution of electromagnetic wave at . (d) Spatial distribution of ion density at . The plasma density is for (e) and (f). (e) Distribution of the electrostatic wave in space obtained for the time window and transverse region . (f) Spatial distribution of the ion density at . and are normalized by , where and respectively are the electron mass and electron charge. is normalized by .

Fig. 5. (a) The spatial–temporal distributions of electrostatic wave. (b) Distributions of the electrostatic wave in space obtained for the time window . (c) The spatial–temporal distributions of ion density. (d) Energy distributions of electrons at different times. and respectively are normalized by and .