SFP Transceiver Modules

SFP transceiver module is a hot-swappable small package module in SFP package, with a maximum speed of 10.3G and an interface of LC. SFP transceiver module is mainly composed of lasers.

SFP is the abbreviation of SMALL FORM PLUGGABLE, which can be simply understood as an upgraded version of GBIC.

The dimension is reduced by half compared with the GBIC module, only the size of a thumb. More than double the number of ports can be configured on the same panel. Other functions of the SFP module are basically the same as GBIC. Some switch manufacturers call it miniaturized GBIC (MINI-GBIC)

Composition of SFP Transceiver Module
SFP transceiver module composes of laser (including transmitter TOSA and receiver ROSA), circuit board IC and external accessories. The external accessories are composed of shell, base, PCBA, pull ring, buckle, unlocking piece, and rubber plug. For easy identification, the parameter type of the module is generally identified by the color of the pull ring.

Types of Speed Rate
According to the speed rate, there are 155M/622M/1.25G/2.125G/4.25G/8G/10G, 155M and 1.25G are widely used in the market, 10G technology is gradually maturing and its demand is growing.

Types of Wavelength
According to the wavelength, there are 850nm/1310nm/1550nm/1490nm/1530nm/1610nm. 850nm wavelength is SFP multimode, and its transmission distance is below 2KM. 1310/1550nm wavelength is single mode, and the transmission distance is above 2KM. Relatively speaking, the prices of these three wavelengths are cheaper than the others.

The optical transceiver module is easy to be confused without any label. So, the manufacturer will distinguish in the color of the pull ring. For example, the black one is for multi-mode 850nm wavelength, the blue one is for 1310nm wavelength; the yellow one is for 1550nm wavelength, and the purple one is for 1490nm wavelength, etc.

Multi-mode
Almost all multimode fiber sizes are 50/125um or 62.5/125um, and the bandwidth (the amount of information transmitted by the fiber) is usually 200MHz to 2GHz. The multimode optical transmitter and receiver can transmit up to 5 kilometers through multimode optical fiber. Light-emitting diodes or lasers are used as light sources. The color of pull ring or external shell is black.

Singlemode
The size of single-mode fiber is 9-10/125um, and it has the characteristics of unlimited bandwidth and lower loss than multimode fiber. The single-mode optical transmitter and receiver is mostly used for long-distance transmission, sometimes up to 150 to 200 kilometers. It uses LD or LED with narrow spectral line as the light source. The pull ring or external color is blue, yellow or purple.