How to choose 40G QSFP+ optical module？

40G QSFP+ optical module refers to the transmission rate of 40G, and the package of this optical module is QSFP+. 40G optical module has four independent full-duplex transceiver channels, each channel of the transceiver rate of 10G, thus forming a 40G transmission rate, ETU LINK Optical Communication (ETU-LINK) will introduce the 40G QSFP + optical module what types are there.

IEEE organization for 40G QSFP + optical module to develop a variety of transmission protocols, common are: 40G BASE-SR4, 40G BASE-LR4, 40G BASE-BiDi, 40G BASE-ER4, etc., the interface type of these optical modules, transmission distance, working wavelength are not the same, the following is the parameter list of 40G optical modules for you reference.

As shown in the table above, 40G SR4, 40G ER4? and 40G BIDI are multimode optical modules that require the use of OM3/OM4 fiber optic patch cords for transmission, which are suitable for equipment interconnection within the data center due to the short transmission distance; 40G SR4, 40G eSR4 and 40G PSM4 interface types are MPO interfaces, this type of interface can not only achieve 40G link connection, but also use MPO-LC patch cord to achieve 40G link and 10G link connection; LX4, LR4, ER4 interface type is LC, need to be used with single-mode fiber OS2 patch cord, the transmission distance is more than 2KM, the farthest is 40KM.