The 100G optical modules are booming in 2017. And there are many types of 100G optical transceivers on the market such as for example CFP modules and QSFP28. Anyone who has experienced in using optical transceivers may know each sort of transceiver provides their own functional mode. And knowing this functional mode allows you to pick the suitable 100G optics for your networks.

CFP SR10

CFP SR10 is a 100Gbps parallel transceiver for optical communication applications. It supports link lengths of 100 m and 150 m on laser-optimized OM3 and OM4 cable. This transceiver converts the 10-channel 10Gbps electrical input data into 10-channel 850nm optical signals and then coupling them into ribbon fiber array (MPO connector) for 100Gbps optical signal transmission. On the receiver side, the optical signals are changed into electrical data for 10 output channels. Following is the functional diagram.

CFP LR4

CFP LR4 is another person in 100G CFP modules. But its working procedure is just a little not the same as CFP SR10 module . CFP LR4 uses four channels for transmitting and four channels for receiving. It uses four WDM optical signals and multiplexes them right into a single channel for 100G transmission. On the receiver side, it demultiplexes the 100Gbps signals into four WDM optical signals and converts them into four output channels. Its functional diagram is below.

QSFP28 SR4

QSFP28 SR4 can be a parallel optical transceiver. It provides four channels for transmitting and four channels for receiving, each with the capacity of 25Gb/s procedure for an aggregate data rate of 100Gbps on 100 meters of multimode fiber, which is comparable to the CFP LR4. However, the QSFP28 SR4 doesn’t multiplex the optical signals into WDM for transmitting. Its functional diagram is definitely shown below.

QSFP28 PSM4

The functional mode of QSFP28 PSM4 is a lot similar compared to that of QSFP28 SR4. It uses four independent transmit and receive channels. Each channel operates at 25Gbps. The difference mainly is based on the fiber they make use of. QSFP28 PSM4 works on single mode ribbon fiber cable, while QSFP28 SR4 works on multimode ribbon fiber cables.

QSFP28 CWDM4

Similar to PSM4, the QSFP28 CWDM4 also uses 4x25Gbps to attain 100Gbps. However the difference can be that the CWDM4 utilizes an optical MUX and DEMUX to lessen the fiber it requires, which is similar to the CFP LR4. It just requires a duplex single mode fiber cable for connecting two 100G CWDM4 optical modules. At the moment, CWDM4 links are found in both 100G CFP4 or the QSFP28 optical transceivers .