Detailed explanation of basic concepts and usage precautions of SFP optical modules

Time : Aug. 18, 2022    View : 67

The optical module is composed of optoelectronic devices, functional circuits and optical interfaces. The optoelectronic devices include two parts: transmitting and receiving. Simply put, the function of the optical module is photoelectric conversion. The transmitting end converts the electrical signal into an optical signal, and after transmission through the optical fiber, the receiving end converts the optical signal into an electrical signal. Now, optical modules are getting more and more attention in communication operations. SFP optical modules are the most popular one among modules. Next, we summarize the common knowledge of SFP optical modules from the following aspects. Interested friends Let’s take a look together.


  1. Overview of SFP optical modules

       ①. Definition of optical module

       The packaging method of SFP optical modules is hot-swappable small packages. Now the maximum speed can reach 10G, and there are many LC interfaces. The abbreviation of SFP is Small Form-factor Pluggable, which can be simply understood as an upgraded version of GBIC. The volume of the SFP optical module is reduced by half compared to the GBIC optical module, and the number of ports can be more than doubled on the same panel.


       ②. Optical module composition

       SFP optical modules are composed of lasers, circuit board ICs and external accessories. The external accessories include shells, unlocking parts, buckles, bases, pull rings, rubber plugs, PCBA, and the color of the pull rings can help us differentiate the parameter types of the module.


       ③. Open the SFP optical module

       GBIC and SFF are optical modules, and are gradually replaced by SFP optical modules with the rapid development of the network. It’s opening up in the direction of miniaturization and hot swapping. SFP optical modules inherit the hot-swap characteristics of GBIC, and also learn the advantages of SFF miniaturization. The use of LC headers greatly increases the port density of network equipment, and is used to the trend of rapid network opening, and has been widely used. Although there are now many higher-tech and newer optical transceiver products, SFP transceivers will still be around for a long time. After SFP, the opening of optical modules is mainly towards higher rates, and now there are 10G, 40G, 100G and other optical modules.

Basic Concepts and Precautions of SFP Optical Modules


  1. Tips for using SFP optical modules

       The module has inappropriate operation during the operation, which simply constitutes the failure of the optical module. In this situation, don’t worry, check carefully and analyze the specific elements. Generally, there are two main types of optical module failures, namely, the failure of the transmitter and the failure of the receiver. The most common elements are as follows:

       ①. The end face of the optical fiber connector used has been polluted, which constitutes secondary pollution of the optical port of the optical module;

       ②. The optical port of the optical module is exposed to the environment, and dust enters and pollutes it;

       ③. Use inferior fiber optic connectors, etc. Therefore, attention should be paid to the cleaning and protection of optical modules in normal use. After use, it is recommended to plug the dust plug. Since the optical contacts of the module are not cleaned, it is very likely to affect the signal quality, or cause line problems and bit error problems.


  1. 3. Precautions for SFP Optical Module Equipment

       ①. Turn up the pull ring of the SFP optical module vertically, clamp the top buckle, hold both ends of the SFP optical module with your hands, and gently push it into the SFP slot until the SFP module is in close contact with the slot (you can feel the SFP optical module). The top and bottom shrapnel catch the SFP slot)

       ②. Wear an anti-static wrist when installing/pulling out the SFP optical module

       ③. In the absence of an excellent grounding method, do not directly plug and unplug the SFP optical module, which may cause the SFP optical module or the electronic components in the SFP slot to be electrostatically broken down, resulting in device damage.

       ④. Pull the pull ring of the SFP optical module to the horizontal position to remove the fixed contact between the shrapnel and the SFP slot. Forcibly pulling out the SFP optical module will damage the shrapnel or the buckle in the slot.


       Summary: SFP optical module is a small hot-pluggable optical transceiver integrated module, which is widely used in communication operations. There are many types of SFP optical modules, such as: BIDI-SFP, electrical SFP, CWDM SFP, DWDM SFP, SFP+ optical module Wait. In addition, for the same type of XFP, X2, and XENPAK optical modules, SFP optical modules can not only be directly connected to them, but also have the characteristics of lower cost.