Fiber Jumper

Structure

Optical fiber jumper (also known as optical fiber connector) means that both ends of the optical cable are equipped with connector plugs to realize the active connection of the optical path; Pigtail. Optical fiber patch cord (OpticalFiberPatchCord/Cable) is similar to coaxial cable, except that there is no mesh shielding layer. In the center is the glass core through which light propagates. In a multimode fiber, the diameter of the core is 50μm~65μm, which is roughly equivalent to the thickness of a human hair. The single-mode fiber core has a diameter of 8 μm to 10 μm. The core is surrounded by a glass envelope with a lower refractive index than the core to keep the optical fiber in the core. On the outside is a thin plastic jacket to protect the envelope.

The classification and overview of optical fiber jumpers are as follows

Optical fiber jumpers (also known as optical connectors), which are connected to optical modules. There are many types of optical fiber connectors, and they cannot be used mutually. The SFP module is connected to the LC fiber optic connector, and the GBIC is connected to the SC fiber optic connector. The following is a detailed description of several commonly used optical fiber connectors in network engineering:

①FC type optical fiber jumper: The external reinforcement method is a metal sleeve, and the fastening method is a turnbuckle. Generally used on the ODF side (most used on the distribution frame)

②SC type optical fiber jumper: the connector for connecting the GBIC optical module, its shell is rectangular, and the fastening method is using plug-in bolts Style without rotation. (The most used on routers and switches)

③ST-type optical fiber jumper: often used in optical fiber distribution frames, the shell is round, and the fastening method is turnbuckles. (For 10Base-F connection, the connector is usually ST type. It is often used in optical fiber distribution frames)

④LC type optical fiber jumper: the connector for connecting the SFP module, which adopts the modularity for easy operation The jack (RJ) latch mechanism is made. (Commonly used by routers)

Main parameters

Product description

Classification

Optical fiber jumpers can be divided into common silicon-based optical fibers according to different transmission media Single-mode, multi-mode patch cords, and other optical fiber patch cords such as plastics as transmission media; according to the structure of the connector, it can be divided into: FC patch cords, SC patch cords, ST patch cords, LC patch cords, MTRJ patch cords Wire, MPO jumper, MU jumper, SMA jumper, FDDI jumper, E2000 jumper, DIN4 jumper, D4 jumper, etc. in various forms. The more common fiber optic jumpers can also be divided into FC-FC, FC-SC, FC-LC, FC-ST, SC-SC, SC-ST, etc.

Single-mode Fiber (Single-modeFiber): Generally, fiber jumpers are indicated by yellow, and the connectors and protective sleeves are blue; the transmission distance is longer.

Multi-mode fiber (Multi-modeFiber): Generally, fiber optic jumpers are indicated by orange, and some are indicated by gray. Connectors and protective covers are in beige or black; the transmission distance is shorter.

Features

1. Low insertion loss;

2. Good repeatability;

3. Large return loss;

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4. Good mutual insertion performance;

5. Good temperature stability;

6. Strong tensile performance.

Application

Optical fiber patch cord products are widely used in: communication room, fiber to the home, local area network, fiber optic sensor, fiber optic communication system, fiber optic connection transmission equipment, national defense combat readiness, etc. It is suitable for cable television network, telecommunication network, computer optical fiber network and optical test equipment. The subdivision 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

Use attention

Optical fiber The transceiver wavelengths of the optical modules at both ends of the jumper must be the same, that is to say, both ends of the fiber must be optical modules of the same wavelength. The simple way to distinguish is that the colors of the optical modules must be the same. In general, short-wave optical modules use multi-mode optical fibers (orange optical fibers), and long-wave optical modules use single-mode optical fibers (yellow optical fibers) to ensure the accuracy of data transmission.

Do not over-bend and loop the optical fiber during use, as this will increase the attenuation of the light in the transmission process.

After using the fiber jumper, be sure to use a protective cover to protect the fiber connector. Dust and oil will damage the coupling of the fiber.

If the fiber connector is dirty, you can clean it with a cotton swab dipped in alcohol, otherwise it will affect the communication quality.

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

2. The minimum bending radius of the optical fiber is not less than 150mm when in use.

3. Protect the ferrule and the end face of the ferrule to prevent bumps and pollution. Wear a dust cap in time after disassembly.

4. Do not look directly at the end face of the optical fiber during laser signal transmission.

5. When there is damage caused by man-made and other force majeure factors, the damaged fiber jumper should be replaced in time.

6. Read the instructions carefully before installation, and install and debug under the guidance of the manufacturer or dealer’s engineer.

7. If the optical fiber network or system is abnormal, you can use the troubleshooting method to test one by one. When testing or troubleshooting jumper faults, you can do a continuity test first, and you can usually use a visible laser pointer to judge the entire optical fiber link. Or further use a precision optical fiber insertion loss return loss tester to test its various indicators. If the indicators are within the qualified range, the jumper indicates normal, otherwise, it is unqualified.

Selection Guide

According to the termination type, there are three types of optical fiber jumpers: ST-ST, SC-SC, ST-SC. According to the type of fiber, there are two types of single-mode fiber and multi-mode fiber. The jumper length specifications are 0.5m, 1m, 2m, 3m, 5m, 10m, etc. According to the cable outer sheath material, 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 the building and the fire resistance requirements of the materials, the integrated wiring system should take corresponding measures. When laying cables or optical cables in flammable areas and building shafts, flame-retardant cables and optical cables should be used; in large public places, flame-retardant, low-smoke, and low-toxic cables or optical cables should be used; adjacent equipment rooms or handover rooms Flame-retardant wiring equipment should be used.

Installation points

See "Code for Acceptance of Buildings and Buildings Integrated Wiring System Engineering" GB/T50312-2000 and "Code for Construction and Acceptance of Buildings and Buildings Integrated Wiring System Engineering" CECS89 : 97 requirements.

Differences

1. Single-mode modules generally use LD or LEDs with a narrow spectral line as the light source. The size of the coupling component is well matched with the single-mode fiber, and the single-mode fiber can be used for transmission. Longer transmission distance   

2. Multi-mode modules generally use lower-priced LEDs as light sources, and the size of the coupling components matches well with the multi-mode fiber.

Pigtail is also called pigtail cable, only one end has a connector, and the other end is a broken end of an optical fiber core, which is connected to other optical fiber cores by fusion splicing, and often appears in the optical fiber terminal box. Used to connect optical cables and optical transceivers (couplers, jumpers, etc. are also used between them).

The optical fiber connector is a device for detachable (movable) connection between the optical fiber and the optical fiber. It precisely connects the two end faces of the optical fiber to maximize the optical energy output by the launching optical fiber. Coupled to the receiving fiber, and minimize the impact on the system due to its intervention in the optical link, which is the basic requirement of the optical fiber connector. To a certain extent, the optical fiber connector also affects the reliability and performance of the optical transmission system.

Technical parameters

1. According to the connector, it can be divided into: FC, ST, SC, LC, MU, MPO, E2000, MTRJ , SMA, etc. The end-face contact methods include PC, UPC, APC.

2. The outer diameter of the optical fiber is Ф0.9mm, Ф2mm, Ф3mm, and the number of fiber cores: single core, double core, 4 core, 6 core, 8 core, 12 core or customer specified.

3. Fiber types can be divided into: G652B, G652D, G655, G657A1, G657A2, 50/125, 62.5/125,

OM3(50/125-150), OM4 (50/125-300) and so on.

4. The color of the connector can be divided into: blue (usually used for single-mode PC, UPC connector), beige, gray (usually used for multi-mode connector), green (APC connector), water blue ( OM3), the color of the tail sleeve can be divided into: gray, blue, green, white, red, black, cyan.

5. Length of connection line: Customize.

Grinding method

"/" indicates the cross-section process of the optical fiber connector, that is, the grinding method.

"PC" is the most widely used in telecom operators' equipment, and its joint section is flat.

"SC" means that the pigtail connector model is SC connector. The optical interface of the industry transmission equipment generally uses SC connector. SC connector is engineering plastic, which has the advantages of high temperature resistance and not easy to oxidize; ODF side light The interface generally uses FC connectors. FC is a metal connector, but ODF does not have high temperature problems. At the same time, the number of plug-in times of metal connectors is more than that of plastic, and the maintenance of ODF pigtails is more than that of optical fiber pigtails. Other common connector models are: ST, DIN, FDDI.

"PC" means the cross-section process of optical fiber connector, and PC is the most common. The APC model is widely used in radio and television and early CATV. The pigtail head uses an end face with an inclination angle (8 degrees). The inclination is generally invisible. It can improve the quality of the TV signal. The main reason is that the TV signal is analog light modulation. When the coupling surface of the connector is vertical, the reflected light Return to the original path. Because the unevenness of the refractive index distribution of the fiber will return to the coupling surface again, although the energy is small at this time, the analog signal cannot completely eliminate the noise, so it is equivalent to superimposing a weak signal with time delay on the original clear signal. It is ghosting on the screen. The inclination of the pigtail headband can prevent the reflected light from returning along the original path. Generally, digital signals do not have this problem.

There is also a "UPC" process. Its attenuation is lower than that of PC. Generally, the flange of the equipment with special needs is generally FC/UPC. Foreign manufacturers use FC/UPC for fiber jumpers inside ODF racks to improve the ODF equipment's own indicators.

How to test

How to test whether the fiber optic patch cord is qualified?

Use the insertion loss tester First, use a light pen to test whether the jumper is light, and make sure that the fiber is not broken. The measured index is a general carrier-grade index: insertion loss is less than 0.3dB and return loss is greater than 45dB.

The performance testing of optical fiber patch cords is divided into:

1. Optical performance testing, including return loss/insertion loss testing. The test instrument can use FibKey7602 return loss/insertion loss integrated tester.

2. End face geometric shape test, test parameters include radius of curvature, vertex offset, fiber height, etc. The test instrument is an interferometer, and many people use NorlandAC/NC3000 or CC6000 for testing. Especially the CC6000 interferometer is used in more and more factories because of its superior cost performance.

3. Optical fiber end face scratch detection, using video optical fiber magnifying glass for observation, such as many factories use FibViewFV-400PA for inspection. The instrument can give the clearest images, and the operation is extremely simple. Some customers also use FibKey-5600 variable magnification magnifying glass for inspection. This instrument integrates 400 times, 200 times, and 80 times magnifiers, which can clearly and conveniently observe the condition of the fiber end face and the ferrule end face. Of course, you can also use related software for automatic inspection.

4. Optical fiber tensile test, need to test the tensile force that the optical fiber connector can withstand.

5. In the ambient temperature experiment, it is necessary to test the performance indicators of the optical fiber connector under different ambient temperatures.