Single-mode patch cables are the short, visible ends of long links: the duplex LC-LC jumper that connects a single-mode transceiver to the panel where the campus or metro run begins. The GRT range lists single-mode duplex jumpers in the combinations the plant uses — LC-LC-SM in both 10G and gigabit grades — with the catalogue’s 3 m reference length, and single-mode families also appear across the MPO and riser side of the range.
Handling discipline for single-mode jumpers is stricter than for multimode, for one physical reason: the core is roughly a fifth the diameter, so the same dust particle blocks proportionally far more light. Caps on when not plugged, inspection before mating, and no exceptions. The jumpers themselves are inexpensive; the truck roll to find a dirty one is not.
Where SM jumpers are specified
- Transceiver-to-panel connections on campus and metro links
- Riser and inter-building connections
- BiDi links (simplex single-mode)
- Any link whose far end is single-mode — no exceptions downstream
Can I use a single-mode jumper on a multimode link for a short hop?
No. The jumper is part of the link’s fiber discipline; mixing disciplines anywhere in the path breaks the loss budget.
What lengths are standard?
The catalogue reference is 3 m. Project orders can specify other lengths.