Compact dual-polarization silicon integrated couplers for multicore fibers

Area of Science:

• Photonics and Optical Engineering
• Integrated Optics
• Fiber Optic Communications

Background:

• Fiber-to-chip couplers are crucial for optical interconnects, particularly in data centers.
• Existing couplers are primarily designed for standard single-mode fibers, limiting compatibility with multicore and multimode fibers.
• There is a need for compact, efficient couplers that can interface with advanced fiber types.

Purpose of the Study:

• To design and demonstrate a novel compact dual-polarization coupler for interfacing silicon chips with dense multicore fibers.
• To achieve efficient coupling to all cores and both polarizations simultaneously.
• To establish a new benchmark for the smallest footprint in fiber-to-chip couplers.

Main Methods:

• Utilized state-of-the-art optimization algorithms for coupler design.
• Fabricated the coupler on a standard silicon-on-insulator platform.
• Experimentally characterized coupling efficiency, 3 dB bandwidth, and footprint.

Main Results:

• Demonstrated, for the first time, dual-polarization coupling to all cores of a dense multicore fiber.
• Achieved a measured coupling efficiency of -4.3 dB.
• Obtained a 3 dB bandwidth of 48 nm.
• The coupler exhibits a minimal footprint of 200 µm² per core.

Conclusions:

• The developed dual-polarization coupler is the smallest experimentally demonstrated fiber-to-chip coupler on a silicon-on-insulator platform.
• This technology significantly advances the integration of multicore fibers with photonic integrated circuits.
• The device offers a promising solution for high-density optical interconnections in future data centers and communication systems.