Approach to simultaneous suppression of TSRS and SRRS in ICF laser drivers

Stimulated rotational Raman scattering (SRRS) and transverse stimulated Raman scattering (TSRS) are two nonlinear optical effects that limit the load-carrying capacity of inertial-confinement-fusion (ICF) laser drivers. However, each existing suppression strategy reported in the literature addresses only either SRRS or TSRS, failing to suppress both nonlinear effects simultaneously. We propose an innovative pulse stacking method that can effectively suppresses both SRRS and TSRS simultaneously. Unlike conventional pulse stacking, the polarization directions of neighboring sub-pulses are set orthogonal to each other. Theoretical and numerical results show that this "orthogonal-polarization pulse-stacking" approach suppresses both SRRS and TSRS, with greater effectiveness as the number of sub-pulses increases. When the number of sub-pulses reaches 10, the SRRS generation threshold and the TSRS damage threshold are nearly doubled. From the underlying suppression mechanism, it can be inferred that the scheme will likewise suppress other transverse nonlinear effects in high-power systems-such as transverse stimulated Brillouin scattering (TSBS)-providing a useful reference for nonlinear-effect suppression and offering broad application prospects in high-power-laser technology.