First, the guts wavelength: unit nanometer (nm), currently there are three main types

 850nm (MM, multi-mode, low priced but short transmission distance, generally only 500M could be transmitted

 1310nm (SM, single mode, large loss during transmission but small dispersion, generally used for transmission within 40KM

3) 1550nm (SM, single-mode, low loss but large dispersion during transmission, generally used for long-distance transmission above 40KM, and may directly transmit 120KM without relay at the farthes

Second, the transmission rate: refers to the amount of bits (bits) of data transmitted per second, in bps. There are currently four commonly used: 155Mbps, 1.25Gbps, 2.5Gbps, 10Gbps, etc. Transmission rates are usually downward compatible, so 155M optical modules are also called FE (100M) H3C SFP-XG-T , and 1.25G optical modules are also known as GE (Gigabit) optical modules, which are the most used modules in optical transmission equipment. Furthermore, its transmission rate in the optical storage system (SAN) is 2Gbps, 4Gbps and 8Gbps;

Third, transmission distance: identifies the distance that optical signals can be directly transmitted without relay amplification, in kilometers (also called kilometers, km), optical modules generally have the following specifications: multi-mode 550m, single-mode 15km, 40km, 80km And 120km and so forth.Know more:www.oemfibers.com