The length of the QSFP28 (Quad Small Form-factor Pluggable 28) module is typically around 104.7mm.

1、100G QSFP28 SR4

100G QSFP28 SR4 optical module adopts 4-channel 25G NRZ multimode parallel technology, and the transmission distance can reach up to 100m or 300m via 12-core MPO patch cord (OM3/OM4) multimode fiber.It is widely used in 100GBASE-SR4 Ethernet, OTN OTU4, 128GFC, InfiniBand 4x EDR and 5G CPRI/eCPRI links.

2、100G QSFP28 PSM4

100G QSFP28 PSM4 optical module adopts 4-channel 25G NRZ single-mode parallel technology, and the transmission distance can reach up to 2km or 10km through 12-core MPO patch cord (G.652) single-mode fiber, which is widely used in 100G PSM4 Ethernet and InfiniBand 4x EDR links.

3、100G QSFP28 LR4

100G QSFP28 LR4 optical module adopts 4-channel 25G NRZ wavelength-division multiplexing technology (LWDM4), and the transmission distance can reach up to 10km or 20km through duplex LC interface OS2 single-mode fiber, which is widely used in 100GBASE-LR4 Ethernet and OTN OTU4 links.

4、100G QSFP28 ER4

100G QSFP28 ER4 optical module adopts 4-channel 25G NRZ wavelength-division multiplexing technology (LWDM4), and the transmission distance can reach up to 40km through single-mode fiber, which is widely used in 100GBASE-ER4 Ethernet and OTN OTU4 links.

The above mentioned 100G optical modules are available from Walsun.

QSFP28 Compared with CFP series optical modules, QSFP28 optical modules are smaller in size and can realize higher density cabling. In addition, the power consumption of QSFP28 encapsulated optical modules when working is usually no more than 3.5W, while the power consumption of other 100G encapsulated optical modules is usually between 6W and 24W, so it seems that the QSFP28 optical modules consume much less power than CFP/CFP2/CFP4 optical modules. These are the reasons why 100G QSFP28 optical modules are mainly popular than 100G CFP series in the current market.