An All-Optical Diode Based on Plasmonic Attenuation and Nonlinear Frequency Conversion

We present the design of an all-optical diode in a metal-dielectric structure where plasmonic attenuation and quasi-phase-matching are harnessed to greatly improve its performance.Due to the asymmetric design of the second-order nonlinear coefficient,different incident directions will ignite different plasmonic nonlinear processes,which compensate or accelerate plasmonic attenuation.As a result,a unidirectional output of plasmonic signal is achieved.This designed all-optical diode shows advantages of low power consumption,short sample length,high isolation contrast,wide acceptance of structural and initial conditions,and tunable unidirectionality,and becomes of practical interest.