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.