Surface wave splitter based on metallic gratings with sub-wavelength aperture

Area of Science:

• Physics
• Electromagnetism
• Materials Science

Background:

• Surface electromagnetic waves, also known as surface plasmon polaritons, are crucial for nanoscale optical phenomena.
• Metallic gratings are widely used to manipulate electromagnetic waves.

Purpose of the Study:

• To investigate the frequency-dependent splitting of surface electromagnetic waves at the output of a one-dimensional metallic grating.
• To demonstrate asymmetric transmission of surface waves at different frequencies.

Main Methods:

• Fabrication of a one-dimensional metallic grating structure with asymmetric output gratings.
• Experimental measurement of transmission amplitude at different frequencies (16 GHz and 24 GHz) on both sides of the subwavelength aperture.
• Theoretical analysis to support experimental observations.

Main Results:

• The output gratings support surface waves at different frequencies on opposing sides.
• At 16 GHz, transmission was 1,000 times higher on the left side compared to the right.
• At 24 GHz, transmission was 20 times higher on the right side compared to the left.

Conclusions:

• Metallic gratings can effectively guide surface waves to different sides of an aperture based on frequency.
• The observed asymmetric transmission validates the theoretical predictions and highlights the potential for frequency-selective wave manipulation.