Stimulated polariton scattering gain modelling for MgO:LiNbO3 with low-frequency excitations

We present a detailed approach to predicting Stokes gain for stimulated polariton scattering in MgO:LiNbO
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using a gain theory for Gaussian beams that also accounts for the effects of increased polariton damping in the low-frequency wing of the 248 c$\mathrm{m}^{-1}A_{1}$ phonon line. The new theory with the corrected absorption coefficient provides the most accurate route for modelling the gain that applies to real experimental conditions.