The typical attenuation of 1310 nm light in standard single-mode fiber is approximately 0.35 dB/km.

Overview

In single-mode fiber (SMF), the 1310 nm wavelength is widely used because it offers a balance between low attenuation and minimal chromatic dispersion, making it ideal for medium-distance optical communication links . Attenuation refers to the loss of optical signal power as light travels through the fiber, primarily caused by absorption and scattering within the fiber material, as well as bends and imperfections along the fiber path .

Typical Attenuation Values

• Standard single-mode fiber at 1310 nm: ~0.35 dB/km
• Comparison with 1550 nm: 1550 nm has lower attenuation (~0.20–0.25 dB/km), which allows longer transmission distances
• Comparison with multimode fiber at 850 nm: Higher attenuation (~2–3 dB/km), limiting distance

Dispersion Considerations

At 1310 nm, chromatic dispersion is near zero in standard single-mode fiber, which reduces pulse broadening and allows higher data rates over medium distances without significant signal degradation . This makes 1310 nm particularly suitable for metropolitan area networks (MANs), campus networks, and enterprise backbones where distances typically range from a few kilometers up to 40 km .

Practical Implications

• Medium-distance links: 1310 nm is often the default choice for links up to 20–40 km without the need for optical amplification
• Signal integrity: Low dispersion and moderate attenuation ensure minimal signal distortion and reliable high-speed data transmission
• Network design: Engineers select 1310 nm for cost-effective deployment in metro and regional networks, while 1550 nm is preferred for long-haul or submarine links due to its lower attenuation In summary, 1310 nm single-mode fiber provides low attenuation (~0.35 dB/km) and minimal chromatic dispersion, making it ideal for medium-distance optical communication systems where signal clarity and manageable link budgets are essential .