We study the nonlinear Schrodinger system [ begin{cases} displaystyle iu_t+Delta u-u+(frac{1}{9}|u|^2+2|w|^2)u+frac{1}{3}overline{u}^2w=0, idisplaystyle sigma w_t+Delta w-mu w+(9|w|^2+2|u|^2)w+frac{1}{9}u^3=0, end{cases} ] for $(x,t)in mathbb{R}^ntimesmathbb{R}$, $1leq nleq 3$ and $sigma,mu>0$. This system models the interaction between an optical beam and its third harmonic in a material with Kerr-type nonlinear response. We prove the existence of ground state solutions, analyse its stability, and establish local and global well-posedness results as well as several criteria for blow-up.