Permeability enhancement of stratified metal dielectric metamaterial in optical regime

Magnetic response of stratified metal dielectric metamaterial (SMDM) is demonstrated numerically and experimentally. One unit cell of SMDM has a sandwich unit cell consisting of alumina (60 nm)/silver (30 nm)/alumina (60 nm). A Mach–Zehnder interferometer is used to obtain phase information of transmittance and reflectance from which effective permeability is determined. The maximum permeability amounts to 20 and 17 for calculation and experiment, respectively. This huge resonance occurs when the magnetic field is concentrated at the metal layer, while the electric field has a node at the center.

► We demonstrated magnetic response of Stratified metal dielectric metamaterial.
► We extract phase information by using Mach Zehnder interferometer.
► The effective permeability of SMDM was confirmed to deviate significantly from unity.
► The magnetic field is strongly enhanced around the dielectric–metal–dielectric interfaces at resonance frequency.