Ultralow sidelobe midinfrared optical phased array based on a broadband metasurface

Area of Science:

• Photonics and Metamaterials
• Optical Engineering

Background:

• Optical phased arrays (OPAs) are crucial for beam steering applications.
• Existing OPA designs often face limitations in bandwidth, steering range, and sidelobe suppression.

Purpose of the Study:

• To propose an all-solid-state and ultralow sidelobe optical phased array (OPA).
• To design a broadband, angle-insensitive reflective metasurface for mid-infrared applications.

Main Methods:

• Designing a reflective metasurface with broadband metareflection characteristics (4.3–5.0 µm).
• Simulating an OPA utilizing the designed metasurface, varying structural periodicity for beam deflection.
• Analyzing reflectivity amplitude variation and sidelobe energy levels.

Main Results:

• The metasurface exhibits wide-frequency metareflection from 4.3 to 5.0 µm.
• Continuous beam steering from 0° to 342° with only 10.2% reflectivity amplitude variation.
• Achieved continuous deflection angles up to 44.06° with sidelobe energy below 3.10% of the main lobe energy.

Conclusions:

• The proposed all-solid-state OPA, based on a broadband reflective metasurface, offers excellent beam steering capabilities.
• The design achieves ultralow sidelobes and wide-angle deflection, suitable for advanced optical systems.
• This work demonstrates a promising approach for high-performance optical phased arrays in the mid-infrared.