The Role of Fiber Array in High-Speed Silicon Photonics

The exponential growth of data center network traffic due to cloud computing has spurred demand for advanced optical interconnection. Silicon photonics, with its low-power, high-speed, and compact nature, offers a solution. Fiber Array (FA), an assembly of optical fibers on V-groove substrates, is crucial in this field.

Efficient Optical Signal Coupling

Packaging silicon photonic chips is challenging due to mode field diameter mismatches between silicon waveguides (0.3 – 0.5μm) and single-mode fibers (9μm). FAs address this with high integration. Mode Field Diameter Conversion FAs (MFD FAs) further improve coupling by splicing ultra-high numerical aperture fibers, enabling conversions like 3.2 – 5.5μm to 9μm. For multi-channel silicon optical modules, FAs separate signals across parallel fibers. Curved fiber channels in arrays reduce crosstalk, ensuring reliable transmission.

Meeting High-Speed and High-Density Demands

As 400G, 800G technologies emerge, the need for compact optical components grows. FAs are ideal for high-speed products, offering density and uniformity. In parallel optical transceivers, MT-FA jumpers with 42.5° mirrored ends enable efficient connections. Integrating transmit and receive fibers in one array simplifies silicon module coupling. In coherent optical communication, polarization-maintaining FAs (PM-FAs) preserve light polarization, vital for high-speed transmission.

Driving Technological Integration

FA applications propel silicon photonics integration. Combining polarization-maintaining FA packaging with silicon photonic ICs enables use in 400G/800G modules like QSFP-DD and 400G-ZR, and shows promise in Co-Packaged Optics. While optical imaging FAs, used for tasks like chemical sensing, aren’t directly for communication, they highlight FAs’ potential to expand photonics applications.

In summary, FAs are essential in high-speed silicon photonics, facilitating signal transmission, meeting density needs, and enabling technological progress. Future advancements will likely unlock more FA capabilities.