Selection skills and application characteristics of optical fiber jumper

1、 Introduction to optical fiber jumper

Optical fiber jumper (also known as optical fiber connector) refers to that connector plugs are installed at both ends of the optical cable to realize the active connection of the optical path; One end with a plug is called a pigtail.

Optical fiber patch cord / cable is similar to coaxial cable, but there is no mesh shielding layer. The center is the glass core of light propagation.

In multimode fiber, the diameter of the core is 50 μ m~65 μ m. Roughly equal to the thickness of human hair. The diameter of single-mode fiber core is 8 μ m~10 μ m。 A glass envelope with a lower refractive index than the core is surrounded outside the core to keep the optical fiber in the core. On the outside is a thin plastic jacket to protect the envelope.

2、 Classification of optical fiber jumper

According to different transmission media, optical fiber jumpers can be divided into common single-mode and multi-mode jumpers of silicon-based optical fiber, as well as other optical fiber jumpers with plastic as transmission media;

According to the structure of connector, it can be divided into: FC jumper, SC jumper, St jumper, LC jumper, MTRJ jumper, MPO jumper, Mu jumper, SMA jumper, FDDI jumper, e-multi jumper, din4 jumper, D4 jumper and so on. Common optical fiber jumpers can also be divided into FC-FC, fc-sc, fc-lc, fc-st, SC-SC, sc-st, etc.

Single mode fiber: generally, the optical fiber jumper is represented by yellow, and the connector and protective sleeve are blue; Long transmission distance.

Multi mode fiber: generally, the optical fiber jumper is represented by orange or gray, and the connector and protective sleeve are beige or black; Short transmission distance.

3、 Precautions for use of optical fiber jumper

The transmitting and receiving wavelengths of the optical modules at both ends of the optical fiber jumper must be the same, that is, the two ends of the optical fiber must be optical modules with the same wavelength. The simple way to distinguish is that the color of the optical modules should be the same.

Generally, the short wave optical module uses multimode optical fiber (orange optical fiber) and the long wave optical module uses single-mode optical fiber (yellow optical fiber) to ensure the accuracy of data transmission.

Do not over bend and wrap the optical fiber in use, which will increase the attenuation of light in the transmission process.

After the use of optical fiber jumper, the optical fiber connector must be protected with protective sleeve. Dust and oil stain will damage the coupling of optical fiber. If the optical fiber connector is dirty, it can be cleaned with a cotton swab dipped in alcohol, otherwise the communication quality will be affected.

1. Before use, the ceramic core and end face of the optical fiber jumper must be wiped clean with alcohol and absorbent cotton.

2. The use time is small, and the bending radius is less than 30mm.

3. Protect the plug-in core and the end face of the plug-in core to prevent bumping and pollution. After disassembly, put on the dust cap in time.

4. Do not look directly at the end face of the optical fiber when transmitting the laser signal.

5. In case of damage caused by human and other irresistible factors, the damaged optical fiber jumper shall be replaced in time.

6. Before installation, carefully read the instructions and carry out installation and commissioning under the guidance of the engineer of the manufacturer or dealer.

7. In case of abnormal conditions in the optical fiber network or system, the troubleshooting method can be used to test one by one. When testing or troubleshooting the jumper, you can first conduct the on-off test. Usually, you can use the visible laser pen to judge the lighting of the whole optical fiber link. Or further use the precision optical fiber insertion loss back loss instrument to test its indicators. If the indicators are within the qualified range, the jumper indication is normal, otherwise it is unqualified.

Classification characteristics and selection skills of optical fiber jumper

4、 Characteristics of optical fiber jumper

1. Low insertion loss

2. good repeatability

3. Large return loss

4. Good mutual insertion performance

5. Good temperature stability

6. Strong tensile property

5、 Application of optical fiber jumper

Optical fiber jumper products are widely used in: communication room, optical fiber to home, local area network, optical fiber sensor, optical fiber communication system, optical fiber connection and transmission equipment, national defense and war preparedness, etc. It is applicable to cable TV network, telecommunication network, computer optical fiber network and optical test equipment. Subdivided, it is mainly used in several aspects.

1. Optical fiber communication system

2. Optical fiber access network

3. Optical fiber data transmission

4. Optical fiber CATV

5. Local area network (LAN)

6. Test equipment

7. Optical fiber sensor

6、 Selection of optical fiber jumper

According to the termination type, the optical fiber jumper mainly has the following three types: st-st, SC-SC and st-sc.

According to the type of optical fiber, there are mainly single-mode optical fiber and multimode optical fiber.

The specifications of jumper length include 0.5m, 1M, 2m, 3M, 5m, 10m, etc.

According to the material of cable outer sheath, it can be divided into ordinary type, ordinary flame retardant type, low smoke halogen-free type (lzsh), low smoke halogen-free flame retardant type, etc.

According to the fire rating of buildings and the fire resistance requirements of materials, corresponding measures shall be taken for the generic cabling system.

Flame retardant cables and optical cables shall be used for laying cables or optical cables in flammable areas and building shafts;

Flame retardant, low smoke and low toxicity cables or optical cables should be used in large public places;

Flame retardant wiring equipment shall be used in adjacent equipment rooms or handover rooms.

7、 Difference between optical fiber jumper and optical fiber pigtail

The optical fiber jumper is used to make the jumper from the equipment to the optical fiber wiring link. It has a thick protective layer, which is generally used for the connection between the optical transceiver and the terminal box.

Pigtail is also called pigtail. Only one end has a connector, while the other end is the broken end of an optical cable core. It is connected with other optical cable cores through fusion. It often appears in the optical fiber terminal box to connect the optical cable with the optical fiber transceiver (coupler, jumper, etc. are also used between them).

Optical fiber connector is a device for detachable (movable) connection between optical fiber and optical fiber. It connects the two end faces of optical fiber accurately, so that the optical energy output by transmitting optical fiber can be coupled to receiving optical fiber to the limit, and the impact on the system caused by its intervention in optical link can be minimized. This is the basic requirement of optical fiber connector. To a certain extent, the optical fiber connector also affects the reliability and performance of the optical transmission system.

8、 How to check whether the optical fiber jumper is qualified

First, use the plug-in and return loss instrument to measure whether the jumper is illuminated with a light pen to determine whether the optical fiber is not broken. The general indicators of carrier level test: the insertion loss is less than 0.3dB and the return loss is greater than 45dB

The performance test of optical fiber jumper is divided into:

1. Optical performance test

Including back loss / insertion loss test. Fibkey 7602 back loss / insertion loss integrated tester can be used as the test instrument.

2. End face geometry test

The parameters tested include radius of curvature, vertex offset, fiber height, etc. The testing instrument is interferometer. Many people use Norland AC / nc3000 or cc6000 for testing. In particular, cc6000 interferometer is used by more and more factories because of its superior cost performance.

3. Optical fiber end face scratch detection

Use video optical fiber magnifying glass for observation. For example, many factories use fibview FV multi PA for inspection. The instrument can give clear images and is extremely simple to operate. Some customers also use fibkey-5600 variable magnification magnifier for detection. The instrument integrates multiple, 200X and 80x magnifiers, which can clearly and conveniently observe the end face of optical fiber and core insertion end face. Of course, relevant software can also be used for automatic inspection.

4. Optical fiber tension test

It is necessary to test the tensile force that the optical fiber connector can withstand.

5. Ambient temperature test

It is necessary to test the performance index of optical fiber connector under different ambient temperatures.

9、 Common applications of common optical fiber jumper interfaces

The common interface types of optical fiber jumper are FC, SC, St, PC, APC and LC. The optical fiber jumper of FC connector is mostly used on the distribution frame, while the optical fiber jumper of SC connector is mostly used on the router switch. In addition, there are various types of optical fiber interfaces, such as MTRJ, MPO, mu, SMA, FDDI, Edo, D4, etc.

Optical fiber jumper interface

Optical fiber jumper connector is an issue that users must consider when purchasing optical fiber jumper. Understanding the meaning of various optical fiber jumper connectors can help users find the products they want faster.

FC type optical fiber jumper

The external strengthening method is metal sleeve, and the fastening method is turnbuckle. FC connector is generally used in telecommunication network, and a nut is screwed to the adapter, which has the advantages of firmness and anti dust, but the disadvantage is that the installation time is slightly longer. Generally, it is used on ODF side (most of them are used on distribution frame, and most of them are also used for optical transceiver)

SC type optical fiber jumper

The shell of the connector connecting GBIC optical module is rectangular, and the fastening method is plug-in pin latch type without rotation. The SC connector is directly plugged in and out, which is very convenient to use. The disadvantage is that it is easy to fall out (it is often used on routers and switches)

St type optical fiber jumper

After the st head is inserted, there is a bayonet fixed on the half circumference of rotation, which has the disadvantage that it is easy to break; It is commonly used in optical fiber distribution frame. The shell is round and the fastening method is turnbuckle. (for 10base-f connections, the connector is usually st type.

LC type optical fiber jumper

The connector connecting the SFP module is made of a modular jack (RJ) latch mechanism that is easy to operate. (default LC interface of SFP optical module)

MT-RJ optical fiber jumper

Square optical fiber connector with integrated transceiver, one end of double fiber transceiver. MTRJ optical fiber jumper consists of two high-precision plastic connectors and optical cables. The external parts of the connector are precision plastic parts, including push-pull plug clamping mechanism. It is suitable for indoor applications in telecommunications and data network systems.