Characteristics and connection scheme of 100G QSFP28 ER4 optical module

The 100G QSFP28 optical module has the characteristics of high density and low power consumption, which not only meets the current network requirements, but also prepares for future network expansion. It is an ideal optical module solution for large data centers. Its standards are mainly defined by IEEE and MSA, among which IEEE defines the standards of SR4, LR4, ER4, and ZR4. This article will talk about the 100G QSFP28 ER4 optical module.

The 100G QSFP28 ER4 optical module complies with QSFP MSA, IEEE 802.3ba, 100GBASE-ER4 Lite and OTU4 standards, "ER" means extra long reach (extend reach), the optical signal is amplified by SOA before passing through the APD photodetector, and can pass single mode Optical fiber realizes 40km ultra-long distance transmission. Using WDM multiplexing wavelength division technology, the wavelength is 1295.56-1309.14, using LC duplex connector, with DDM, supporting 100G Ethernet and OTU4, the power consumption is less than 3.8W under the operating temperature of 0-70 °C, in line with the data center green energy saving requirements.

However, because the BER requirement of 100G QSFP28 ER4 is better than that of 1E-12 optical module without FEC front-end error correction function, but the existing APD technology cannot meet its receiving sensitivity, and the SOA volume is too large for the QSFP28 package, so , Many optical module manufacturers in the industry define non-standard 100G base ER4 Lite optical modules in QSFP28 package, and the maximum transmission distance can reach 30km without FEC.

working principle:

The 100G QSFP28 ER4 optical module transmitter can work on four LAN WDM bands of 1295nm, 1300nm, 1305nm and 1310nm. The optical signals in these four bands are multiplexed by a WDM wavelength division multiplexer and then transmitted on a single-mode fiber through an industry-standard LC connector. At the receiving end, the SOA amplifies the signal before the WDM wavelength division multiplexer decomposes the signal into individual channels.

Connection scheme:

To achieve 100G long-distance transmission of 40km in enterprises or data centers, whether it is direct connection or interconnection, QSFP28 ER4 optical module is the best choice.

1. Direct connection scheme:

QSFP28 ER4 supports 100G direct connection, and the longest transmission distance can reach 40km. Just insert two 100G QSFP28 ER4 modules into the 100G switch port, and then use an LC duplex single-mode jumper to connect, providing an economical solution for long-distance applications of 100GE ports between equipment rooms.

2. Data center interconnection scheme:

The 100G QSFP28 ER4 optical module is also suitable for connecting data centers located in different geographical locations, and supports long-distance high-speed interconnection between 100G data centers. It is a convenient and economical interconnection solution.