Reconciling measured scattering response of 3D metamaterials with simulation

Abstract

Membrane projection lithography is used to create 3-dimensional unit cells in a silicon matrix decorated with metallic inclusions. The structures show pronounced resonances in the 4–16 µm wavelength range and demonstrate direct coupling to the magnetic field of a normally incident transverse electromagnetic (TEM) wave, a behavior only possible for vertically oriented resonators. Qualitative agreement between rigorous coupled wave analysis (RCWA) simulation and measured scattering response is shown. COMSOL simulations show that slight variations in both metallic inclusion and silicon unit cell physical dimensions can have large impact in the scattering response, so that design for manufacture of 3D metamaterial structures for applications should be done with care.

Keywords

• 3D metamaterials
• Split ring resonator
• Micro fabrication