2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/125033Nonlinear excitation of second sound in superfluid solutions He3-He4 by light waves due to their absorption is discussed. Nonlinear wave equations that model the interaction of second-sound waves with light waves are derived, the expression for the nonlinear interaction length is obtained and an order-of-magnitude numerical estimate of the distance at which a second-sound wave could be amplified from a fluctuation level up to observable values is performed.5 pages, to be published in Proceedings of the XIX session of the Russian Acoustical SocietySoft Condensed Mattertext