Efficient unidirectional and broadband vertical-emitting optical coupler assisted by aperture-coupled nanopatch...

Area of Science:

• Photonics and Integrated Optics
• Antenna Theory
• Nanophotonics

Background:

• Vertical-emitting optical couplers are essential for photonic integrated circuits (PICs).
• Traditional grating couplers suffer from inefficient bidirectional light emission (upward and downward), limiting device performance.
• A need exists for efficient, unidirectional vertical couplers in advanced PICs.

Purpose of the Study:

• To propose and demonstrate a novel nanopatch antenna array for efficient vertical light emission.
• To achieve high directionality and broad operating bandwidth in optical couplers.
• To enhance the efficiency of light coupling in integrated photonic devices.

Main Methods:

• Design of a nanopatch antenna array inspired by microwave patch antenna principles.
• Simulation and analysis of emission directionality, bandwidth, and free-space gain.
• Comparison of the proposed design with traditional waveguide grating antennas.

Main Results:

• The nanopatch array achieved an impressive up-to-down emission directionality of 12.91 dBc.
• A wide operating bandwidth exceeding 400 nm was simultaneously realized.
• The design demonstrated a significantly higher free-space gain of 24.27 dBi compared to grating antennas.

Conclusions:

• The novel nanopatch antenna array offers a highly efficient and unidirectional solution for vertical light emission.
• The demonstrated broadband and high-gain characteristics make it suitable for various integrated photonics applications.
• This technology holds promise for advancing inter-chip photonic interconnects, optical communications, and sensing.