Layered Babinet complementary patterns acting as asymmetric negative index metamaterial.

Area of Science:

• Nanophotonics
• Metamaterials
• Optical Engineering

Background:

• Investigating optical responses of subwavelength periodic arrays is crucial for advanced photonic devices.
• Understanding asymmetric transmission and dichroism is key to controlling light-matter interactions at the nanoscale.

Purpose of the Study:

• To demonstrate azimuthal orientation and handedness dependence of optical responses in multilayered Babinet complementary miniarrays.
• To explore the negative index material (NIM) phenomenon and its associated electromagnetic responses.
• To propose the multilayer as an ultrathin NIM and nonreciprocal nanophotonic element.

Main Methods:

• Fabrication of multilayered nanostructures with subwavelength periodic arrays.
• Illumination with linearly and circularly polarized light, including counter-propagating beams.
• Analysis of asymmetric transmission, dichroism, reflectance, and absorptance spectra.
• Characterization of electric and magnetic dipole and multipole responses.

Main Results:

• Observed asymmetric optical responses, including transmission and dichroism, dependent on polarization and orientation.
• Demonstrated the negative index material (NIM) phenomenon with overlapping electric and magnetic dipoles.
• Correlated asymmetric transmission with asymmetric displacement currents and dichroism with tilted magnetic dipoles.
• Identified flat bands in dispersion maps indicating partially dichroic phenomena and maximum Tellegen coefficients.

Conclusions:

• The multilayered nanostructures exhibit significant asymmetric optical responses.
• The demonstrated NIM phenomenon and polarization control capabilities highlight potential applications.
• The proposed multilayer serves as a promising ultrathin NIM and nonreciprocal nanophotonic element.