  An all-optical scheme for simulating non-Markovian evolution of a quantum
system is proposed. It uses only linear optics elements and by controlling the
system parameters allows one to control the presence or absence of information
backflow from the environment. A sufficient and necessary condition for the
non-Markovianity of our channel based on Gaussian inputs is proved. Various
criteria for detecting non-Markovianity are also investigated by checking the
dynamical evolution of the channel.
