A theoretical analysis is presented for the stimulated Raman scattering (SRS) driven by multiple beams with certain frequency differences or bandwidths. The concomitant electrostatic modes are excited by the scattering lights when the pump beams share a common electron plasma wave to drive SRS. This coupling can be suppressed when the frequency difference of the two beams is three times larger than the SRS growth rate of a single beam, where the beams develop their scattering lights independently. To mitigate SRS further under the multibeam irradiation, polychromatic pumps are introduced to reduce the SRS saturation level, where the weakly coupled common modes are heavily damped in hot plasmas. The sidescattering driven by polychromatic light in inhomogeneous plasmas is significantly reduced due to the wavevector mismatch of daughter waves. Particle-in-cell simulations confirm our theoretical analysis and demonstrate that the strength of multibeam SRS and the hot electron production in inhomogeneous plasmas can be controlled at a low level by polychromatic light with a few percentage bandwidth (), even in the non-linear regime.

对由具有一定频率差异或带宽的多光束驱动的受激拉曼散射 (SRS) 进行了理论分析。当泵浦光束共享一个共同的电子等离子体波来驱动 SRS 时，伴随的静电模式被散射光激发。当两束光的频率差比单束光的 SRS 增长率大三倍时，这种耦合可以被抑制，其中光束独立地产生散射光。为了在多光束照射下进一步减轻 SRS，引入了多色泵以降低 SRS 饱和水平，其中弱耦合共模在热等离子体中受到严重阻尼。由于子波的波矢失配，在非均匀等离子体中由多色光驱动的侧向散射显着减少。)，即使在非线性状态下。