Based on the rapidly growing demand for broadband, more and more data centers are beginning to deploy 40G networks. Therefore, a large number of 40G network transmission applications have sprung up in the market one after another. These include: 40G QSFP+ optical modules, 40G direct-connect cables and 40G active optical cables, etc. Today, the most used one is 40G active optical cables. Active optical cables have played a major role in the move to fiber-optic connectivity in traditional data centers. Why does 40G active optical cable become a topic of subversive force in 40G network?

Active optical cable refers to a communication cable that needs to use external energy to convert electrical signals into optical signals, or convert optical signals into electrical signals in the communication process. The optical transceivers at both ends of the optical cable provide photoelectric conversion and optical transmission functions. The 40G active optical cable has four parallel transmission channels, and the data transmission speed of each channel is 10Gb/s, so as to achieve a transmission speed of 40Gbps. When in use, one end of the 40G active optical cable is connected to the 40G QSFP+ connector, and the other end can be connected to the QSFP+ connector, SFP+ connector or LC connector. It is the main transmission medium for high-performance computing and data centers emerging as an alternative to copper cables, with strong stability and flexibility.

But why are active optical cables so popular?

Under normal circumstances, when the passive cable is transmitted to 10 meters at the rate of 10-Gb/s, the signal attenuation is very large, and the active optical cable can make up for this shortcoming. When using, the user only needs to unplug the pluggable cable interface, and then plug in the active optical cable repeater or connector of the same shape and size. For the line card problem, the optical interface and the electrical interface play exactly the same role. Of course, the benefits of active optical cable for 40G network transmission are far more than this. We will describe its advantages in detail below.

Low cost – Compared with 40G QSFP+ optical modules, 40G active optical cables can be regarded as the most cost-effective products in data centers. Active optical cable is a product that encapsulates two optical modules and optical cables together, which realizes the seamless connection between optical modules and jumpers. Because it fixes the optical fiber inside the module, fewer optical components are used in the fabrication process. The 40G QSFP+ optical module is usually connected to the fiber jumper, and the cost of the fiber jumper is also a lot of money. In addition, because the optical port of the active optical cable is not exposed, it has extremely high reliability, so there is no opportunity for dust or other contaminants to take advantage of, and the cost of cleaning and maintenance of the optical fiber port is avoided.

Small size – Direct attach cables are notoriously bulky and bulky, making effective cable management difficult in data centers. Also, the properties of electrical signals and electromagnetic interface (EMI) also have an impact on the performance of direct attach cables. Active optical cables are specifically created to replace copper cables. They are lighter in weight, smaller in size, more resistant to electromagnetic interference, low-level interconnect losses, and can also reduce power requirements. They are widely used in storage, networking and high High-speed data connectivity for performance computing (HPC) applications.

Ease of UseActive Optical Cable encapsulates optical modules and fiber patch cords together, so it enables fast and efficient fiber optic connections. In addition, because it has the characteristics of high bandwidth and light weight, it is convenient for users to plug and unplug. In addition, active optical cables are generally used in data communication infrastructure, and it is easy to operate even for those who do not have professional optical fiber knowledge.

From the current point of view, the general trend of “optical advance and copper retreat” is clear at a glance, and the future will be the era of “all-optical network”. Especially driven by higher bandwidth and more application demands in the cloud computing environment, active optical cable technology has penetrated into every corner of the high-speed interconnection market. With the gradual expansion of the active optical cable market, it will not only bring about disruptive changes to the 40G network, but also to the telecommunications and data communication transceiver markets.

Published On: April 8th, 2022 / Categories: Learning Center / Tags: , , /