How to tell the difference between single mode and multimode SFP？

There are several ways to tell the difference between single mode and multimode SFP (small form-factor pluggable) transceivers:

1. Labeling: Single mode SFPs are typically labeled as "SM" or "S" for single mode, while multimode SFPs are labeled as "MM" or "M" for multimode.

2. Transmission Distance: Single mode SFPs are designed for longer transmission distances, usually up to 10 kilometers to 100 kilometers, while multimode SFPs are intended for shorter transmission distances, typically up to 550 meters to 2 kilometers.

3. Core Size: Single mode SFPs use a smaller core size (approximately 9 microns) to allow only one mode of light to propagate, while multimode SFPs use a larger core size (approximately 50 or 62.5 microns) to allow multiple modes of light to propagate.

4. Color Code: The connector housing of single mode SFPs is typically blue, yellow, or green, while multimode SFPs are usually orange or beige.

5. Application: Single mode SFPs are commonly used for telecom and long-distance data transmission, while multimode SFPs are used for short-distance applications such as local area networks (LAN) and data centers.

By considering these factors, you can easily differentiate between single mode and multimode SFP transceivers.

SFP Single Mode vs Multimode –

PARAMETER	SM SFP	MM SFP
Abbreviation for	Single Mode SFP	Multimode SFP
Distance Supported	Can Support Greater distance than MM Fiber. SM Fiber can support distance value as high as 80 km or even 120 km	Used for short distance transmission reaching 100 m and 500 m
Cost	SM SFP is costly	MM SFP is cheaper than SM SFP
Core Size	Single-mode fiber has a smaller core (9 micron)	Multi-mode fiber has a broader core (62.5 and 50 micron)
Wavelength supported	works mainly in 1310nm and 1550nm wavelength	Works mainly in 850nm wavelength
Preferential usage	Used inside LAN for Switch ,Router and Server connectivity inside Building or Data Center	Required on WAN connectivity like Service provider Handoff to office/Data Center or connectivity between offices.
Colour schema	The colour coded bale clasp and colour arrow on label are generally blue, yellow or purple. And the colour of compatible fiber optic patch cord is yellow.	Their colour coded bale clasp and colour arrow on label are black and the used fiber optic patch cord is usually orange.