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40G Optical Transceiver Development and Challenges

Under the pressure of bandwidth, data centers urgently need high-density transmission rates. There are many different models of 40G optical modules, such as 40GBASE-SR4. 40G optical modules also encountered many challenges in the process of development. Many engineers may be confused about what 40GBASE-SR4 is when choosing optical modules. This article will introduce the development and challenges of 40G optical modules, and introduce in detail what 40GBASE-SR4 is.

The 40G Ethernet Overview

When 40G/100G is used as a new technology, breakthroughs and innovations in some key technologies will be involved in all aspects of its R&D and deployment, which also brings a series of new technologies to chip developers, equipment manufacturers, and end-users. challenges and problems.

The processing capability of routers/switches (including overall machine capacity, port density, high-speed table lookup, traffic management, thermal design, and energy-saving design) will give 10 times the bandwidth of each port (relative to 10G ports). System design brings higher requirements. Usually, when designing the switching capacity of the system, the speedup ratio (speedup) is considered, that is, a certain amount of additional information overhead is required when packets are exchanged between boards. The speedup ratio is generally between 1.5 and 2, which means that if the physical interface is 100G, the

The required backplane switching capacity is 150G~200G, and the two-way is 300G~400G. If the product will provide a large capacity of 4*100G per slot in the future, this requires the system to provide a switching capacity of 1.2T~1.6T for each slot. If it is designed according to SerDes of 10Gbps, 60-80 pairs of high-speed signals are required. So many high-speed signals bring huge challenges to IT technicians to make a system design, single-board design, and PCB design. When 100G processing performance is achieved, huge power consumption and heat will be generated. How to achieve efficient ventilation and heat dissipation is gradually becoming an extremely important and critical aspect of high-end equipment system design.

What is 40GBASE-SR4?

The 40GBASE SR4 QSFP+ transceiver modules achieve maximum transmission distances of 100m and 150m over laser-optimized OM3 and OM4 multimode fibers, respectively. It can realize high-bandwidth 40G optical links on 12-core parallel fibers, and it is terminated by an MPO/MTP multi-fiber connector. In addition, it can use 4 x 10G transmission mode, so that 40GBASE-SR4 can interoperate with the 10GBASE-SR interface. At the same time, its working wavelength is the same as 10GBASE-SR, which is 850nm. It is a good choice for data centers to build 4x10G optical connections.


This article introduces the difficulties encountered in the development of 40G Ethernet. The operators overcame these challenges, and finally led to the birth of QSFP+ 40G optical modules such as 40GBASE-SR. Data centers can also be convenient to build a 4x10G optical link. If you want to know more about 40GBASE-SR4 optical modules, you can contact QSFPTEK, QSFPTEK is a company specializing in the production of optical modules, including a series of products such as 40GBASE-SR4.