Understanding 100G QSFP28 ER4 Optical Module

Nowadays, 100G QSFP28 optical modules are popular in the optical communication industry because of their small size, low power consumption, and high density. There are many types of 100G QSFP28 optical modules on the market, such as 100G QSFP28 SR4 optical module, 100G QSFP28 LR4 optical module, 100G QSFP28 PSM4 optical module, 100G QSFP28 CWDM4 optical module, etc. Their transmission distance ranges from 500m to 10km. However, if you want to reach a longer distance, you need to use a 100G QSFP28 ER4 optical module which has a longer transmission distance. This article will introduce this 100G optical module with a transmission distance of up to 40km from the definition, working principle, and application.

Brief description of 100GBASE-ER4 standard

Before introducing the 100G QSFP28 ER4 optical module, let's first understand the 100GBASE-ER4 standard. 100GBASE-ER4 standard is defined by the IEEE 802.3ba working group, which supports DWDM technology and can transmit signals in the 1310nm wavelength band through single-mode fiber patch cables. The "ER" represents the extra long distance (extend reach), using SOA amplification before the optical signal through the PIN photodetector to achieve 40 kilometers of transmission.

 100G QSFP28 ER4 Optical Module 

100G QSFP28 ER4 Optical Module Overview

The 100G QSFP28 ER4 optical module is compliant with QSFP MSA, IEEE 802.3ba, 100GBASE-ER4 Lite, and OTU4 standards, and can transmit up to 40km over single-mode fiber, supporting 100G Ethernet and OTU4 with a maximum power consumption of 4.5W.

100G QSFP28 ER4 optical module working principle

The 100G QSFP28 ER4 optical module transmitter works on four LAN WDM wavelength bands: 1295nm, 1300nm, 1305nm, and 1310nm. The optical signals on these four bands are multiplexed by WDM wavelength division multiplexer and then transmitted through LC duplex single-mode fiber patch cable. At the receiving end, the optical signal is first amplified by the SOA (PIN receiver is used to convert the optical signal back to an electrical signal), and then the signal is broken down into individual channels by the WDM WDM multiplexer.

100G QSFP28 ER4 Application Solution

Whether it is an enterprise network or data center, 100G direct or interconnect, 100G QSFP28 ER4 optical module is a good choice for long-distance transmission up to 40 km.

Direct Connect Solution

Simply insert two 100G QSFP28 ER4 optical modules into the QSFP28 ports of two 100G switches and connect them with an LC duplex single-mode fiber patch cable to achieve a 100G direct connection with a maximum transmission distance of 40 km.

Interconnect Solutions

The 100G QSFP28 ER4 optical module is also suitable for connecting data centers in different geographic locations, supporting remote high-speed interconnection between 100G data centers, which is a convenient and cost-effective interconnection solution.

100G QSFP28 ER4 optical module vs 100G QSFP28 ER4 Lite optical module

The BER requirement of 100G QSFP28 ER4 optical module is better than 1E-12 without FEC front-end error correction function optical module. however, the existing APD technology does not meet the requirement of the 100G QSFP28 ER4 optical module for receiving sensitivity. Therefore, many optical module manufacturers in the industry have defined non-standard 100GBASE-ER4 Lite optical modules in the QSFP28 package, which can reach a maximum transmission distance of 40km when using FEC and 30km when not using FEC.