What Is The Difference Between a Singlemode SFP and Multi-mode SFP?
The Singlemode SFP and Multi-mode SFP mean the SFP transceivers will work on different types of optical fibers; as in a Singlemode SFP will work with Singlemode fiber only, and a Multi-mode SFP will work with Multi-mode fiber only.
So, what’s the different between them? And what should we notice when using them?
Singlemode fiber has much tighter tolerances for optics used. The core is smaller and the laser wavelength is narrower. This means that SMF has the capability to carry a higher bandwidth at much longer transmission distances. Singlemode SFPs work mainly in the 1310nm and 1550nm wavelengths and is mostly used in a long distances transmission environment reaching 2km, 10km, 40km, 60km, 80km and 120km.
Singlemode SFP Color Coding
SFPs are identified by the color of the Bale Clasp. Though there is still a lack of total conformity; generally speaking, Singlemode SFPs use this color coding:
- Gray color coded bale clasp designates the 1470 nm SFP
- Violet color coded bale clasp designates the 1490 nm SFP
- Blue color coded bale clasp designates the 1510 nm SFP
- Green color coded bale clasp designates the 1530 nm SFP
- Yellow color coded bale clasp designates the 1550 nm SFP
- Orange color coded bale clasp designates the 1570 nm SFP
- Red color coded bale clasp designates the 1590 nm laser SFP
- Brown color coded bale clasp designates the 1610 nm SFP
- The color of the compatible fiber optic patch cord or pigtail is yellow
Multi-mode fiber uses a much bigger core and usually uses a longer wavelength of light. Because of this, the optics used in Multi-mode have a higher capability to gather light from the laser. In practical terms, this means the optics are cheaper. The common Multi-mode SFPs work in 850nm wavelength and is only used for short distance transmission reaching 100m and 500m. Though it’s not able to transport for long distance, it can transport many kinds of optical signals.
Multi-mode SFP Color Coding
As with Singlemode SFPs, Multi-Mode SFPs are identified by the color of the Bale Clasp:
- Black color coded bale clasp designates a Multi-mode SFP
- The color of the compatible fiber optic patch cord or pigtail is orange
- Ensure that the SFPs in both ends of the fiber patch cord are of the same wavelength and consistent in color coding
- Avoid extreme bends or wind fiber optic cables as this will increase the attenuation of transmitted light
- If no SFP/XFP is in use in your host equipment, cover the empty port with a blank to protect the optical port
- In case you’re wondering what SFP means: Small Form-factor Pluggable
- The terminology behind fiber optics can be tricky. Let Multicom help you Talk the Talk of Fiber Optics