Flat optical phased array receiver incorporating an on-chip metalens concentrator

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Metamaterials

Background:

• Optical phased arrays (OPAs) are crucial for beam steering and optical detection.
• Traditional OPAs face challenges in phase control and miniaturization.
• On-chip integration of optical components is a key goal in modern photonics.

Purpose of the Study:

• To design and propose a novel flat optical phased array (OPA) receiver.
• To overcome the limitations of conventional OPAs in phase-controlled light detection.
• To demonstrate enhanced in-plane coupling efficiency over a wide field of view.

Main Methods:

• The proposed OPA receiver integrates a grating antenna, a free-propagation region (FPR) with an on-chip metalens concentrator (OCMC), and a tapered waveguide.
• The OCMC is fabricated using subwavelength slot meta-atoms with varying lengths, quantized to 16 phase levels.
• Light coupling at a slanted angle is achieved by imposing a space-dependent phase on incident light via the OCMC.

Main Results:

• The OCMC enables angle-tolerant coupling of light to the output port without phase modulators.
• The OCMC plays a pivotal role in enhancing in-plane coupling efficiency across the field of view.
• The proposed flat OPA receiver demonstrates efficient phase-controlled light detection at slanted angles.

Conclusions:

• The developed flat OPA receiver with an integrated OCMC offers a promising solution for advanced optical detection systems.
• This design facilitates miniaturization and improved performance in optical phased array receivers.
• The angle-tolerant coupling mechanism enhances the robustness and applicability of the OPA receiver.