Corning LEAF Bare Optical Fiber
LEAF — Large Effective Area Fiber — is the non-zero dispersion-shifted fiber that most of the world's long-haul DWDM infrastructure was built on in the late 1990s and 2000s. It remains one of the largest deployed fiber types in the ground and is still used for matching and test-spool applications.
- ITU-T standard
- G.655.C
- Mode field diameter
- ~9.6 µm @ 1550 nm
- Effective area (Aeff)
- ~72 µm²
- Attenuation @ 1550 nm
- ≤ 0.20 dB/km
LEAF is ITU-T G.655.C: positive dispersion in the range of +2 to +6 ps/nm/km at 1550 nm, effective area approximately 72 µm², attenuation 0.20 dB/km or below at 1550 nm, mode field diameter about 9.6 µm at 1550 nm. The combination of low-but-nonzero positive dispersion and large effective area was the design answer to two problems that killed pure dispersion-shifted fiber for DWDM: four-wave mixing (solved by keeping dispersion away from zero) and self-phase modulation (mitigated by large Aeff).
DWDM systems on LEAF fiber carry C-band and L-band channel plans. The positive dispersion requires dispersion compensation in the amplifier spans, typically using dispersion-compensating fiber (DCF) modules at amplifier sites. LEAF is not a substitute for G.652.D fiber in systems that do not use dispersion compensation.
For active systems still running on LEAF plant, and for test spools where a specific dispersion value is required, we supply LEAF bare fiber in standard and custom lengths. Tell us the required spool length and connector termination and we will quote.
Specifications
| ITU-T standard | G.655.C |
|---|---|
| Mode field diameter | ~9.6 µm @ 1550 nm |
| Effective area (Aeff) | ~72 µm² |
| Attenuation @ 1550 nm | ≤ 0.20 dB/km |
| Dispersion @ 1550 nm | +2 to +6 ps/nm/km (positive NZ-DSF) |
| Dispersion slope | ~0.060 ps/nm²/km |
| PMD coefficient | ≤ 0.1 ps/√km |
Typical Applications
- Mid-span splicing and legacy matching for installed LEAF long-haul plant
- Dispersion test spools requiring a known positive NZ-DSF dispersion value
- System testing of DWDM equipment designed for G.655.C fiber
- Research and characterization of nonlinear impairments in LEAF spans
Why Order Corning Fiber from Aumictech?
We source directly from the Corning authorized channel. Every spool ships with documentation, including reel ID and fiber code.
0.5 km to 1,000 km on a single order. Mix lengths across spools. Choose FC, SC, or LC connectors per spool end, or leave ends bare.
Certificate of compliance and OTDR test data available on request. Required for carrier acceptance testing and network documentation.
Continental US next-day and two-day air available. International shipping on request. Most orders confirmed within one business day.
Frequently Asked Questions
Why did LEAF become the dominant long-haul fiber for DWDM?
True dispersion-shifted fiber (DSF, G.653) moved the zero-dispersion wavelength to 1550 nm, which seemed ideal for single-channel systems. But when WDM was introduced, having zero dispersion at the operating wavelength caused four-wave mixing between channels, which generated crosstalk products that grew with channel count. LEAF solved this by keeping a small but nonzero positive dispersion in the C-band. The large effective area also reduced nonlinear phase noise from self-phase modulation. The combination enabled dense WDM channel plans that DSF could not support.
Can LEAF fiber carry 100G coherent channels?
Yes. LEAF fiber is fully capable of carrying coherent 100G DWDM signals. The positive dispersion is manageable with coherent DSP or dispersion compensation, and the large effective area reduces nonlinear noise. Many long-haul LEAF systems have been upgraded from legacy 10G to coherent 100G by deploying new transponders on existing fiber without replacing the plant.
Is LEAF still manufactured by Corning?
Corning LEAF is a legacy product that has been superseded for new builds by G.654 fiber families with better loss and larger effective area. However, it remains available through certified channel stock for matching and testing applications. Contact us with the required length and we will confirm availability.