Efficient and broadband metalens based coupling architecture for silicon photonics chips

Area of Science:

• Photonics
• Nanotechnology
• Materials Science

Background:

• Efficient fiber-to-chip coupling is crucial for silicon photonics.
• Conventional grating couplers have limited bandwidth (~30 nm), hindering applications like wavelength-division multiplexing.

Purpose of the Study:

• To develop a novel fiber-to-chip coupling architecture for silicon photonics.
• To achieve broadband and efficient coupling exceeding conventional limitations.

Main Methods:

• Proposed a new architecture using a 45° planar reflector and a metalens on a silicon-on-insulator (SOI) platform.
• Optimized the coupler design for operation around 1550 nm.
• Utilized finite-difference time-domain (FDTD) simulations for analysis.

Main Results:

• Achieved a maximum coupling efficiency of -0.73 dB.
• Demonstrated a 1 dB bandwidth of 300 nm.
• Showcased good tolerance to misalignments and process variations.

Conclusions:

• The proposed metalens-based coupler offers a significant advancement in broadband fiber-to-chip coupling.
• The architecture is compatible with standard microfabrication, enabling practical applications.
• This technology can benefit wavelength-division multiplexing and other high-bandwidth photonic systems.