Stokes pulse shapes in steady-state stimulated Raman scattering in hydrogen

Abstract

Stimulated Raman scattering (SRS) is a non-linear phenomenon primarily used for laser frequency conversion into multiple laser lines. Its high conversion efficiency and simplicity make the technique ideal in many applications such as lidar measurements, generation of short pulses, time-gated imaging, and low light-level imaging. H₂ and D₂ are often used as the Raman active media because these are relatively simple molecules with large Raman shifts and scattering cross sections. It has been widely demonstrated in experiments that the Stokes light is emitted in the forward direction using nanosecond laser pulses with a duration shorter than the laser pulse. SRS in the transient regime has been widely studied by several authors. In this paper we present a numerical solution of the equations governing the time evolution of the pump and the Stokes pulses. These pulses are studied for varying gas pressure and input pulse energy.