Selection and use of optical modules

The optical module is composed of optoelectronic devices, functional circuits and optical interfaces, etc. The optoelectronic devices include two parts: transmitting and receiving. The optical module can convert electrical signals into optical signals at the transmitting end through photoelectric conversion, and then convert the optical signals into electrical signals at the receiving end after being transmitted through optical fibers.

Any optical module has two functions of sending and receiving, performing photoelectric conversion and electro-optical conversion, so that the optical modules are inseparable from the devices at both ends of the network. Nowadays, there are often tens of thousands of devices in a data center. To realize the interconnection of these devices, optical modules are indispensable. Today, optical modules have become a segment of the data center.

Selection of Optical Modules

With the wide range of optical modules, more and more customers have begun to pay attention to the stability and reliability of the modules themselves. There are three kinds of popular optical modules on the market now: original optical modules, second-hand optical modules and compatible optical modules. As we all know, the price of original optical modules is very high, and many manufacturers can only stay away. As for second-hand optical modules, although the price is relatively low, the quality is not guaranteed, and the phenomenon of packet loss often occurs after half a year of use.

Therefore, many manufacturers have turned their attention to compatible optical modules. Indeed, the performance of the compatible optical module is almost the same as the original optical module in use, and the price is several times cheaper than the original optical module, which is why the compatible optical module can be hot. However, the products on the market are mixed, and many merchants are shoddy and confused, which makes the selection of optical modules difficult. Let's talk about the selection of optical modules in detail below.

First of all, the first question, how do we distinguish between new optical modules and second-hand optical modules?

As mentioned above, second-hand optical modules often lose packets after half a year of use, which is caused by unstable optical power and reduced optical sensitivity. If we have an optical power meter, we can take it out and test it to see if its optical power is consistent with the parameters on the data sheet. If the discrepancy is too large, it is a second-hand optical module.

Then observe the after-sales use of the optical module. The service life of a normal optical module is 5 years. It is basically difficult to see the quality of the optical module in the first year, but it can be seen in the second or third year of its use.

Secondly, it depends on the compatibility between the optical module and the device. Before purchasing, consumers need to communicate with suppliers to inform them which brand of equipment they need to use.

Finally, we also need to see how the temperature adaptability of the optical module is. The temperature generated by the optical module itself during operation is not high, but its general working environment is in the computer room or on the switch. Too high or too low temperature will affect its optical power, optical sensitivity and other parameters. In general, the temperature range of the optical module used is 0~70°C. If it is in an extremely cold or extremely hot environment, you need to use an industrial-grade -40~85°C optical module.

Tips for using optical modules

If you find that the function of the optical module fails during use, don't worry, check carefully and analyze the specific reasons. Generally, there are two main types of optical module function failures, namely, the failure of the transmitter and the failure of the receiver.

The most common reasons are as follows:

The optical port of the optical module is exposed to the environment, and the optical port is polluted by dust entering;

The end face of the optical fiber connector used has been polluted, and the optical port of the optical module is polluted twice;

The end face of the optical connector with pigtail is improperly used, and the end face is scratched;

Use poor quality fiber optic connectors.

Therefore, after purchasing an optical module correctly, you should also pay attention to the cleaning and protection of the optical module during use. After normal use, it is recommended to plug the dust plug when not in use. Because if the optical contact is not clean, it may affect the signal quality, which may cause LINK problems and bit error problems.