FTTH networks predominantly use single-mode fiber due to its high bandwidth and long-distance transmission capabilities.

Single-Mode Fiber in FTTH

Fiber-to-the-Home (FTTH) delivers broadband services directly to residences using optical fibers, bypassing traditional copper lines for the final connection . The fiber used in these networks is typically single-mode, which has a narrow core (about 9 µm) that allows only one mode of light to propagate . This design minimizes modal dispersion, enabling high-speed data transmission over long distances without significant signal degradation . Single-mode fiber is ideal for connecting homes to central network hubs, ensuring reliable and high-quality internet, video, and telephony services .

Advantages of Single-Mode Fiber for FTTH

• High Bandwidth: Supports increasing demand for data-intensive applications like streaming, gaming, and cloud services .
• Long-Distance Transmission: Can carry signals over several kilometers without repeaters, making it suitable for residential deployments spread across urban and suburban areas .
• Future-Proofing: Single-mode fiber can accommodate higher data rates and evolving technologies, reducing the need for frequent infrastructure upgrades .

Multimode Fiber in FTTH

While multimode fiber exists, it is generally used for shorter indoor connections or specific indoor setups where distances are limited, such as within a building or between floors . Its larger core (50–62.5 µm) allows multiple light modes, which increases modal dispersion and limits long-distance performance, making it less suitable for typical FTTH deployments .

Conclusion

In summary, FTTH networks are primarily deployed using single-mode fiber because it provides the necessary high bandwidth, long-distance capability, and reliability required for modern residential broadband services. Multimode fiber may be used in limited indoor scenarios, but single-mode remains the standard for connecting homes to the broader optical network .