Corning SMF-28 ULL S+ bare optical fiber spool
ITU-T G.654.C

Corning SMF-28 ULL S+ Bare Optical Fiber

SMF-28 ULL S+ is a G.654.C ultra-low-loss fiber designed specifically for cost-optimized submarine space division multiplexing systems. It targets the SDM cable architectures that pack high fiber counts into submarine cable designs by optimizing the fiber geometry for minimum insertion loss per fiber pair.

ITU-T standard
G.654.C
Target application
Submarine SDM
Attenuation @ 1550 nm
≤ 0.168 dB/km
Coating options
242 µm or 200 µm

The S+ designation indicates a submarine-focused variant of the ULL family. Pure silica core construction delivers attenuation at or below 0.168 dB/km at 1550 nm. Available in both 242 µm and 200 µm coating, with 200 µm being the standard for submarine cable designs where fiber density per cable cross-section is a primary design parameter.

SDM submarine systems use high fiber counts — 6, 12, or more fiber pairs per cable — to increase system capacity without proportionally increasing cable cost. The per-fiber optical performance of each pair must be as good as possible, and the fiber geometry must allow the cable to be packed tightly enough to remain within the allowable cable diameter for the chosen armoring design.

Specifications

ITU-T standard G.654.C
Target application Submarine SDM
Attenuation @ 1550 nm ≤ 0.168 dB/km
Coating options 242 µm or 200 µm

Typical Applications

  • Submarine space division multiplexing cable systems
  • High-density submarine cable designs requiring tight fiber packing
  • Trans-oceanic routes at 100G and above

Why Order Corning Fiber from Aumictech?

Certified channel stock

We source directly from the Corning authorized channel. Every spool ships with documentation, including reel ID and fiber code.

Any length, any connector

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.

NIST-traceable documentation

Certificate of compliance and OTDR test data available on request. Required for carrier acceptance testing and network documentation.

Ships from Pleasant Grove, UT

Continental US next-day and two-day air available. International shipping on request. Most orders confirmed within one business day.

Frequently Asked Questions

What is space division multiplexing in submarine cables? +

SDM refers to submarine cable designs that carry multiple fiber pairs, typically 6 to 12 or more, in a single armored cable. Traditional submarine cables used 4 or 6 fiber pairs. SDM cables increase capacity by adding more pairs while controlling the cable outer diameter. Each fiber pair still carries standard DWDM wavelength-division multiplexed channels, so total system capacity scales with both fiber count and per-fiber spectral efficiency.