Driven by the demand for high broadband from cloud data centers, artificial intelligence, and the Internet of Things, the penetration rate of 100G networks is getting higher and higher, and the demand for 100G high-speed optical modules is also increasing rapidly. Next, ETU-LINK will introduce the application of 100G QSFP28 optical module in the data center.

The network structure in the data center can be divided into three layers: the core layer, the aggregation layer and the access layer. Generally, 100G QSFP28 optical modules are used for the interconnection of the aggregation layer switch and the core layer switch and the interconnection between the core layer switches. The 100G QSFP28 optical module is mainly used to access the QSFP28 port on the switch, and the following types of optical modules are common.

1. 100G QSFP28 SR4（EQ28510X-3MCD01）

100G QSFP28 SR4 optical module adopts 4-channel 25G NRZ multi-mode parallel technology, MPO interface, and the transmission distance can reach up to 70m or 100m through 12-core MPO (OM3/OM4) multi-mode fiber patch cord. It is widely used in 100GBASE-SR4 Ethernet, OTN OTU4, 128GFC, InfiniBand 4x EDR and 5G fronthaul CPRI/eCPRI links.

2. 100G QSFP28 LR4（EQ2xx10X-3LCD10）

The 100G QSFP28 LR4 optical module adopts 4-channel 25G NRZ wavelength division multiplexing technology (LWDM4), dual LC interfaces, working wavelengths of 1295, 1300, 1304, 1309nm, and the transmission distance through OS2 single-mode fiber is up to 10 kilometers. It is widely used in 100GBASE-LR4 Ethernet and OTN OTU4 links.

3. 100G QSFP28 ER4（EQ2xx10X-3LCD40）

The 100G QSFP28 ER4 optical module adopts 4-channel 25G NRZ wavelength division multiplexing technology (LWDM4), the center wavelength is 1295, 1300, 1305, 1310nm, dual LC interface, the maximum rate is up to 103.1Gbps. The transmission distance can be up to 40 kilometers through single-mode fiber. It is widely used in 100GBASE-ER4 Ethernet and OTN OTU4 links.

At present, 100G Ethernet technology has matured, and the deployment of 100G networks by major enterprises, institutions or governments has gradually stepped onto the right track. The 100G optical module supports 4×25G data transmission mode, and because of its high port density, low power consumption and low cost, it is deeply favored by data center users.