Stimulated rotational Raman scattering suppression by pulse stacking

Abstract

Suppression of stimulated rotational Raman scattering (SRRS) is essential for the effective long-distance transmission of high-intensity laser pulses in air. In this work, a method for SRRS suppression is proposed based on the reconstruction of the initial laser pulse via subpulse stacking. The proposed method can suppress SRRS significantly and doubles the threshold distance when the initial laser pulse is stacked using 30 subpulses; this capability is attributed to the mutually perpendicular polarization directions of the adjacent subpulses. Additionally, the SRRS gain decreases even further if different phases are added to adjacent subpulses. This pulse stacking scheme also has potential for use in the suppression of other nonlinear effects, including transverse stimulated Raman scattering and transverse stimulated Brillouin scattering in large aperture optical components. There may be some difficulties in the implementation of such a scheme, and the energy losses that occur during the stacking process may even be greater than the losses due to SRRS, but we believe that the proposed method can serve as an inspiration for SRRS suppression scheme design.