How to choose fiber jumpers for optical modules?

With the growth in the use of smart mobile devices, people's work, study and personal daily life are more closely connected to the Internet than ever before, creating a huge demand for data. And given the current era of "big data" where we ourselves generate, process, and store large amounts of data every day, more and more organizations are beginning to realize that managing data more effectively will be the key to their future business success. At this time, the demand for bandwidth is gradually increasing, making fiber jumpers and optical modules more and more important in data transmission between switches and devices. However, with the development of optical modules, the models are becoming more and more complex. Cabling requirements are also getting higher and higher, how do we choose fiber jumpers for optical modules?

1. Introduction to Optical Modules

Optical modules are composed of optoelectronic devices, functional circuits, and optical interfaces. The optoelectronic devices include two parts: transmitter and receiver, which are used for the transmission of optical signals, and are usually inserted into the optical module slots of switches, routers or network interface cards.

The transmission distance of optical modules is divided into three types: short distance, medium distance and long distance. Generally speaking, the transmission distance of 2KM and below is short distance, the transmission distance of 10-20KM is medium distance, and the transmission distance of 30KM and above is long distance.

There are currently three main types of central wavelengths for optical module applications: 850nm, 1310nm, and 1550nm. The 850nm band is mostly used for short-distance transmission, and the 1301nm and 1550nm bands are mostly used for long-distance transmission.

There are many types of optical modules, which are divided into 1*9, GBIC, SFF, SFP, XFP, SFP+, X2, XENPARK, QSFP28, QSFP+, etc. according to the package; 10G, 25G, 40G, 100G, etc. according to the rate; It is conventional wavelength, CWDM, DWDM, etc.; according to the mode, it is divided into single-mode fiber (yellow), multi-mode fiber (orange); according to usability, it is divided into hot-plug (GBIC/SFP, XFP) and non-hot-plug (1 *9, SFF).

2. Introduction to fiber optic patch cords

Fiber optic connectors are installed at both ends of the fiber optic patch cord, which are mainly used in fiber optic communication equipment rooms, FTTH, local area networks, fiber optic data transmission equipment, and test equipment.

According to the transmission mode of light in the fiber, the fiber can be divided into single-mode fiber and multi-mode fiber.

The single-mode fiber has a thin core and can only transmit light in one mode. Therefore, its intermodal dispersion is small and suitable for long-distance communication. It is generally G.635 fiber, the inner diameter of the fiber is generally 9um, and the outer skin is yellow;

The multimode fiber has a thicker core and can transmit light in various modes, but its intermodal dispersion is large, and the intermodal dispersion will gradually increase with the increase of transmission distance. It is suitable for short-range communication. The inner diameter of the fiber is 62.5um and 50um , the rind is orange.

The main types of optical fiber connectors used in optical modules are MPO/MTP, SC, ST, FC, LC, MU, ST, etc.

3. How to choose fiber jumpers for optical modules?

a. Transmission distance and data rate

Optical modules have a variety of different transmission rates and transmission distances. When we choose optical fibers for optical modules, we need to choose a matching optical fiber jumper. The multi-source agreement (MSA) specifies the working wavelengths of various optical modules in detail. , transmission distance and data rate, etc., and lists the suitable fiber types, which also has a certain reference for the selection of fiber jumpers.

b. Interface

When selecting fiber jumpers, the interface is an essential consideration. Usually, the interface of an optical module usually has 2 ports (one for receiving optical signals and one for transmitting optical signals), namely duplex SC or duplex LC, therefore, requires the use of duplex SC/LC fiber. However, the newly launched optical modules in recent years have only one port (which can both receive and transmit optical signals), so simplex optical fibers need to be used. Different connectors can be inserted into different devices. If the ports on both ends of the device are the same, we can use MPO-MPO/LC-LC/SC-SC fiber jumpers. If you want to connect devices with different port types, you can use LC-SC/LC/ST/LC-FC fiber jumpers.

4. Analysis of specific examples

For example, the optical module QSFP-100G-SR4-MM850 has a transmission rate of 100Gbps, and is usually used with multimode fiber (MMF), the center wavelength is 850nm, the connector type is MPO, and 12-core MPO/F-MPO/F fiber can be used Jumper, fiber diameter 50/125um, transmission distance is 70m.