Transmission phase control by stacked metal-dielectric hole array with two-dimensional geometric design

Area of Science:

• Optics and Photonics
• Metamaterials
• Plasmonics

Background:

• Precise control over light transmission phase is crucial for optical devices.
• Metal-dielectric nanostructures offer tunable optical properties.

Purpose of the Study:

• To experimentally demonstrate transmission phase control using stacked metal-dielectric hole arrays.
• To investigate the relationship between structural resonances and phase variation.
• To show the formation of an inclined wavefront for beam steering.

Main Methods:

• Fabrication of stacked metal-dielectric hole arrays with 2D geometric design.
• Excitation of surface plasmon polaritons using periodic hole arrays.
• Utilizing localized resonances within individual holes for dispersion control.
• Interferometric microscopy for direct evaluation of transmission phase at various frequencies.
• Employing a beam steering element with gradually changing in-plane hole shapes.

Main Results:

• Drastic variation of transmission phase with small frequency shifts observed.
• Resonance frequencies determined by laterally propagating surface plasmon polaritons.
• Dispersion determined by localized resonances within each hole.
• Successful demonstration of inclined wavefront formation using a beam steering element.

Conclusions:

• Stacked metal-dielectric hole arrays provide effective transmission phase control.
• The interplay of surface plasmon polaritons and localized resonances dictates phase dispersion.
• The demonstrated beam steering capability highlights potential applications in optical systems.