Metasurface-based Fourier lens fed by compact plasmonic optical antennas for wide-angle beam steering.

Area of Science:

• Metasurface optics
• Plasmonics
• Optical engineering

Background:

• Fourier lenses perform Fourier transforms at the focal plane.
• Metasurfaces offer tunable optical properties.
• Beam steering is crucial for many photonic applications.

Purpose of the Study:

• To report a metasurface-based Fourier lens fed by compact plasmonic optical antennas.
• To achieve wide-angle beam steering with a large field-of-view (FOV).
• To design a novel plasmonic optical antenna for efficient broadside radiation.

Main Methods:

• Design and simulation of a metasurface composed of six elements covering the 2π phase range.
• Development of an ultra-compact plasmonic optical antenna (0.77λ × 1.4λ) for broadside radiation.
• Full-wave simulations to evaluate the performance of the metasurface-assisted beam steering device.

Main Results:

• The metasurface lens achieves a large FOV of ±50°.
• The proposed plasmonic antenna demonstrates high directivity (9.6 dB) and efficiency (>80%) at 1550 nm.
• The metasurface-assisted device achieves a maximum directivity of 21.5 dB and a beam steering range of ±50° with minimal gain drop (2.83 dB).

Conclusions:

• The proposed metasurface-assisted beam steering device offers a wide steering range and good radiation characteristics.
• The compact size and ease of integration make it suitable for various integrated photonic applications.
• This technology shows promise for wireless optical communications, light detection and ranging, and augmented reality.