  We exploit the knowledge of the nonequilibrium potential in a model for the
modulated class A laser. We analyse both, the deterministic and the stochastic
dynamics of such a system in terms of the Lyapunov potential. Furthermore, we
analyse the stochastic response of such a system and explain it again using the
potential in a wide range of parameters and for small values of the noise. Such
a response is quantified by means of the amplification factor, founding
stochastic resonance within specific parameter's ranges.
