Modifications in the optical properties of the porous silicon (PS) nanocomposites with zinc oxide after the swift ion irradiation with Nickel ion of 130 MeV are reported. For the first time the PS/ZnO optical properties were studied with cathodoluminescence and the evolution of white PL along with UV emission is being reported after irradiation. The white light emission has been explained with the help of an increase in the deep level defects in the zinc oxide layer after irradiation.