Fiber optic transceivers are an integral part of optical networks. Transceivers can be classified in terms of data rate, form factor, modulation type, distance etc. Read this article on “How To Choose the Right Transceiver” to learn more about various classifications and what parameters to pay attention to.
Single Mode Vs Multi mode transceiver
Transceivers are classified by modulation type into single and multi-mode transceivers. In optical networks, transceivers are linked by either single or multi-mode fiber cables Single mode transceivers transmit data beyond 500m upwards to 80km and even more. As the name suggests, they require single mode fiber for transmission. Single mode fiber (SMF) has a narrow core that limits dispersion and enables long distance data transmission. Single mode transceivers commonly utilize 1310nm and 1550nm FP (Fabry Perot) or DFB (Distributed Feedback) lasers as light sources. So, for reliable data links beyond 500m, single mode transceivers are the best choice.
Multi-mode transceivers are less expensive than single mode transceivers owing to their inexpensive light source. They commonly utilize 850nm VCSELs (Vertical Cavity Surface Emitting Laser). 850nm allows for higher dispersion, which limits transmission distance. They are best suited for short reach applications, up to 500m.
How to identify single or multi-mode transceivers
The simplest way to identify a single mode transceiver in a network is to look at the color of the attached fiber cable. If the cable is yellow, it is single mode. Orange indicates multi-mode. For data rates of 40G and 100G, the color of the latch on short reach multi-mode transceivers is beige and that of single mode transceivers (2km and more) is blue. CWDM transceivers commonly utilize SMF and depending on the wavelength, the bale latch could be green, orange, purple etc.
Single mode and multi-mode transceivers are not inter-operable in that a connection with a single mode transceiver at one end and a multi-mode transceiver at the other simply will not work. Multi-mode or short reach transceivers are sufficient for most intra data center applications. When designing a network, it’s important to keep in mind future expansions and upgrades. Contact us at firstname.lastname@example.org if you have any questions.