The common 100G optical module packages are CFP/CFP2/CFP4/ and QSFP28. QSFP28 is the most commonly used package due to its smaller size, lower power consumption and higher density. Common QSFP28 optical modules such as QSFP28 SR4, QSFP28 LR4, QSFP28 PSM4, QSFP28 CWDM4 can transmit distances ranging from 500m to 10km. But if you want to reach a longer distance, you need to use QSFP28 ER4, where "ER" means extra long distance (extend reach), can realize 40km distance transmission.
100G QSFP28 ER4 Optical Module Product Working Principle
The 100G QSFP28 ER4 Optical Module is a 100Gb/s module designed for Ethernet 100G BASE-ER4 compliant optical communication applications.The 100G QSFP28 ER4 Optical Module is available in a QSFP28 Multi-Source Agreement (MSA) compliant form factor and supports DDM digital diagnostics. It is designed to meet the harshest external operating conditions, including temperature, humidity, and EMI interference.
Figure 1: QSFP28 ER4 optical module working principle
The module converts four 25Gb/s electrical data inputs into four LAN WDM optical signals, which are then multiplexed into a single channel for 100Gb/s optical transmission. Conversely, at the receiving end, the module demultiplexes the 100Gb/s optical input into four LAN WDM optical signal channels, which are then converted into four electrical output channels.
Four LAN WDM channels centered at 1295nm, 1300nm, 1304nm, and 1309nm. High-performance cooled DFB transmitters and high-sensitivity APD receivers provide excellent performance for 100G Ethernet applications, up to 30km links without FEC and 40km links with FEC.
Features and application scenarios of 100G QSFP28 ER4 optical modules
High-speed transmission: 100Gbps transmission rate makes it ideal for handling large amounts of data and connecting different devices and servers, especially in data centers, cloud computing and other areas.
Long Distance Transmission: ER stands for "Extended Range" which means that it can transmit stably over long distances, usually up to 40 kilometers, and has significant advantages in long distance communication environments, such as in optical backbone networks, and also meets the demand for communication speed in modern cities.
Low Power Consumption: Compared with traditional optical modules, 100G QSFP28 ER4 optical modules usually have lower power consumption, which has a positive effect on energy saving and emission reduction.
Compatibility: 100G QSFP28 ER4 Optical Module It is compatible with a wide range of optical fibers and connection methods, making its application in different environments more flexible and diverse.
QSFP28 ER4 Direct Connect Solution QSFP28 ER4 supports 100G direct connect with a maximum transmission distance of up to 40km. simply insert two 100G QSFP28 ER4 modules into the 100G switch ports and connect them with an LC duplex single-mode patch cable.
Figure 2: QSFP28 ER4 Optical Module Direct Connection
Data Center Interconnection Solutions
The 100G QSFP28 ER4 optical module is also suitable for connecting geographically separated data centers and supports high-speed remote interconnection between 100G data centers, making it a convenient and economical interconnection solution. The figure below shows a basic data center interconnection solution using 100G QSFP28 ER4 optical modules.
Figure 3: QSFP28 ER4 data center interconnects
QSFP28 ER4 optical modules are suitable for enterprises or data centers to realize 100G long distance transmission of 40km, whether it is direct connection or interconnection.
However, due to the 100G QSFP28 ER4 BER requirements are lower than 1E-12 (without turning on the FEC function), but the existing APD technology does not meet the 100G QSFP28 ER4 receive sensitivity, SOA volume for the QSFP28 package is too large, so there is no QSFP28 ER4 optical module on the market to meet the requirements. So many optical module manufacturers in the industry with QSFP28 package definition of non-standard 100Gbase ER4 Lite module, can meet the maximum transmission distance of 40km when the FEC is turned on, and the maximum transmission distance of up to 30km when the FEC is not turned on.
Armitage offers 100G QSFP28 ER4 Lite optical modules, which are compliant with the Ethernet 100Gbase ER4 Lite standard and fully meet the requirements of users for harsh environmental conditions such as temperature, humidity and electromagnetic interference. Standardized 100G QSFP28 ER4 modules will be available soon!
