Corning SMF-28 Ultra Bare Optical Fiber
SMF-28 Ultra is the current default single-mode fiber for most carrier, data center, and FTTH builds. It combines G.652.D optical performance with G.657.A1 bend compliance, lower attenuation than SMF-28e+, and the same 9.2 µm mode field diameter for direct splice compatibility with the installed base.
- ITU-T standard
- G.652.D + G.657.A1
- Mode field diameter
- 9.2 ± 0.4 µm @ 1310 nm
- Coating diameter
- 242 ± 5 µm
- Attenuation @ 1310 nm
- ≤ 0.32 dB/km
Attenuation is 0.32 dB/km or better at 1310 nm and 0.18 dB/km at 1550 nm — measurably better than the 0.34/0.19 specified for SMF-28e+. PMD coefficient is 0.04 ps per root-km, one quarter of the SMF-28e+ value, which matters for coherent 100G and 400G systems on long spans. G.657.A1 compliance means the fiber is rated for 10-turn, 15 mm radius bending without measurable additional attenuation at 1550 nm.
The 9.2 µm mode field diameter is identical to SMF-28e+. That is the critical compatibility number: fusion splicing SMF-28 Ultra to installed SMF-28e+ plant produces the same results as splicing fiber of the same type. You do not need to field-verify splice technique when extending an existing span.
SMF-28 Ultra ships in 242 µm coating as the standard. The 200 µm coating variant is the SMF-28 Ultra 200, listed separately. Both share the same optical numbers — the coating choice depends on cable design constraints.
Specifications
| ITU-T standard | G.652.D + G.657.A1 |
|---|---|
| Mode field diameter | 9.2 ± 0.4 µm @ 1310 nm |
| Coating diameter | 242 ± 5 µm |
| Attenuation @ 1310 nm | ≤ 0.32 dB/km |
| Attenuation @ 1550 nm | ≤ 0.18 dB/km |
| PMD coefficient | ≤ 0.04 ps/√km |
| Bend: 10 turns @ 15 mm | ≤ 0.25 dB added @ 1550 nm |
| Cable cutoff | ≤ 1260 nm |
Typical Applications
- New carrier OSP and metro builds where G.657.A1 handling margin is needed
- Data center long-distance interconnect and backbone cabling
- 100G and 400G coherent DWDM over extended spans
- FTTH distribution where the fiber will be bent through closures
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
Does SMF-28 Ultra splice directly to SMF-28e+ in the field?
Yes. The 9.2 µm mode field diameter and 125 µm cladding are the same on both fibers. A properly executed fusion splice between SMF-28 Ultra and SMF-28e+ produces loss in the same range as same-fiber splices, typically 0.02-0.05 dB on a core-alignment splicer. No special procedures are needed.
Why does G.657.A1 compliance matter for G.652.D fiber?
G.657.A1 defines bend attenuation limits for installed single-mode fiber: 0.25 dB maximum additional attenuation for 10 turns at a 15 mm bend radius. Standard G.652.D fibers may fail this test. The practical relevance is closure and cabinet routing — fiber in a tight bend inside a splice enclosure accumulates signal loss that compounds over the life of the installation. G.657.A1 compliance provides a defined margin for that routing.
Is SMF-28 Ultra available in spool lengths longer than 25 km?
Yes. Standard shipping spools are 2, 5, 10, and 25 km. We can supply custom lengths from under 1 km up to 1000 km on request. Lengths over 25 km are typically delivered on multiple spools unless a custom winding reel is specified. Tell us the required length and we will quote accordingly.