Polarization anisotropic transmission through metallic Sierpinski-Carpet aperture array

Area of Science:

• Photonics and optical metamaterials.
• Nanotechnology and surface plasmon resonance.
• Fractal geometry in optical systems.

Background:

• Extraordinary optical transmission (EOT) is typically achieved with periodic arrays of subwavelength apertures.
• Fractal structures offer unique electromagnetic properties not found in conventional geometries.
• Controlling light polarization and achieving multi-band transmission simultaneously remains a challenge.

Purpose of the Study:

• To investigate EOT through a Sierpinski-Carpet aperture array on a silver (Ag) film.
• To explore the polarization dependence and dual-band transmission characteristics.
• To demonstrate incident angle invariance for potential applications.

Main Methods:

• Fabrication of a Sierpinski-Carpet aperture array on an Ag film.
• Experimental measurement of optical transmission spectra.
• Analysis of polarization dependence and angular response.

Main Results:

• Observed EOT attributed to the fractal geometry of the aperture array.
• Demonstrated simultaneous dual-band transmission.
• Exhibited polarization dependence and significant incident angle invariance within a specific range.

Conclusions:

• The Sierpinski-Carpet aperture array enables novel optical properties, including polarization-manipulated multi-band transmission.
• Fractal designs offer a promising route for advanced optical devices in the infrared spectrum.
• The observed incident angle invariance broadens the potential applications of such structures.