A computational technique was used to study the field propagation through an inhomogeneous thin film using Lippmann-Schwinger equation. The iterative formalism was used which was constructed based on the principle of Born approximation method due to the difficulty in using direct numerical resolution as a result of implicit nature of the function. The computed field value, Ψ through the thin film with variation of the propagation distance was analyzed within the ultraviolet, visible and near of electromagnetic wave and the absorption of the propagated wave by the thin film studied. The energy band gap was also estimated from the computed absorption coefficient obtained from our formalism.