Optical differentiator based on a trilayer metal-dielectric structure

Optical properties of a resonant trilayer metal-dielectric-metal (MDM) structure that consists of an upper metal layer, a dielectric layer, and a metal substrate are investigated. Using a multiple wave interference model, we prove that the reflection coefficient of the MDM structure may strictly vanish. The existence of a reflectance zero makes it possible to use the MDM structure as an optical differentiator. The numerical simulation results presented demonstrate the possibility of optical computation of the first derivative with respect to either time or spatial variable. The obtained results may find application in novel analog optical computing and optical information processing systems.