With the rapid development of data communication and telecommunication transmission technology, the information capacity of optical network has surged, and high-speed bandwidth optical modules are a major research and production hotspot in the field of optical communication. At present, it is in the historical opportunity period of 100G to 400G optical network. The advent of the 5G era will bring the consumption of tens of millions of optical modules. In the next few years, the optical module market will have a market share of more than 30 billion.
The application of the current data center is in a period of rapid development of 100G optical modules. In 2010, the 100G optical communication technology standard has been adopted by ITU-T (International Telecommunication Union), IEEE, and OIF. The three major standards organizations have successively stipulated the 100G technical standards for the 100G line side, the user side and the Interworking. Subsequently, under the extensive attention and promotion of global operators, all links in the industry chain (optical modules, optical transmission equipment, router equipment, and test instruments) have rapidly promoted the commercialization of 100G.
100G optical module
Introduction to Optical Modules
An optical module is a device that converts optical signals and electrical signals in an optical communication system. Its basic structure includes: laser (TOSA) + driving circuit, detector (ROSA) + receiving circuit, multiplexer (MUX), demultiplexing device (DEMUX), interface, auxiliary circuit and shell, etc.
According to the application of different scenarios, different types of optical modules are derived. Specific scenarios include: internal data center, data center interconnection, metropolitan area network, core network, 5G fronthaul network, etc. There are more varieties of optical modules based on factors such as package form, transmission rate, single-mode multi-mode, plug-in mode, operating temperature, and whether digital diagnosis can be performed.
Driven by factors such as technology upgrades and cost reductions, optical modules continue to be "high-speed, miniaturized, and integrated". QSFP (quad-channel SFP interface) series is more and more popular in the market due to its high-speed, high-density, hot-pluggable and other characteristics, and is the most important packaging form of data communication optical modules. For 100G optical modules, SR/LR are mainly packaged in QSFP28, while ER is more packaged in CFP4.
Optical Module Standard
The transmission distance of optical modules is divided into short distance (2km and below), medium distance (2--40km), and long distance (40km and above). At present, among data communication optical modules, medium and short distances occupy the main market share.
There are two key standards organizations for optical modules, IEEE and MSA (Multi Source Agreement), which complement each other and learn from each other. The standards at the beginning of 100GBASE are all proposed by IEEE802.3
In the name of 100GBASE-LR4, LR stands for long reach, that is, 10Km, and 4 stands for four channels, that is, 4*25G. Combined together, it is a 100G optical module that can transmit 10Km.
Since the advent of the 100G network, IEEE, the Multi-Source Agreement (MSA) Industry Alliance and other organizations have formulated multiple standards for 100G optical modules. Taking 100G optical modules as an example, the standards defined by IEEE include 100GBASE-SR4, 100GBASE-LR4, 100GBASE-SR10, etc., and the multi-source agreement (MSA) includes 100G PSM4, 100G CWDM4, 100G CLR4, 100G SWDM4, etc.
Among the many standards, the PSM4 and CWDM4 standards formulated by the Multi-Source Agreement (MSA) industry organization are more suitable for the mainstream 100G QSFP28 optical modules on the market. The following table is the specific situation of some common 100G optical transceiver standards.
In addition to the above-mentioned basic standards, if the optical module is to be applied to the data center on a large scale, the optical module also has requirements in terms of cost, power consumption, reliability and compatibility.
