“…For light propagation in the presence of a highly nonlocal response, the latter smooths out the longitudinal variations in the light-induced index well, thus minimizing back reflections. The inclusion of longitudinal nonlocality improves the agreement between the mathematical model and the physical system [47,48]. In essence, our overall model (i.e., including light evolution and lightmatter interaction) satisfies the paraxial approximation better than standard ones (i.e., when longitudinal nonlocality is neglected).…”