Category Archives: Bulk Fiber Cables

What Is Fiber Optic Cable

With the development of science and technology, the demand for large-scale communication construction is increasing. The fiber optic cable industry has developed rapidly, and has formed a complete industrial chain from fiber preform to optical fiber cable. Then, what is fiber optic cable?

Fiber Optic Cable Definition

To get clear what is fiber optic cable, here starts from the fiber optic cable definition. Also known as optical fiber cable, fiber optic cable is a cable-like component that contains one or more optical fibers that used to carry light. Individually coated with plastic layers, the fiber optic components are contained in a protective tubes suitable for the environment in which the cable will be deployed. With the different types, fiber optic cables are used for different applications, such as long distance communication, or to provide high speed data connections between different parts of a building.

Fiber Optic Cable Structure

The basic structure of fiber optic cable consists of three parts: the core, the cladding, and the coating or buffer. Light propagates mainly along the core which is a cylindrical rod of dielectric material that conducts no electricity. Generally made of glass, the core is surrounded by a layer of material called the cladding. Even though light will propagate along the fiber core without the layer of cladding material, the cladding does perform some necessary functions. The cladding layer is made of a dielectric material. Generally made of glass or plastic, cladding performs the following functions: redounding loss of light from the core into the surrounding air, reducing scattering loss at the surface of the core, and preventing the fiber from absorbing surface contaminants.

Fiber Optic Cable Structure

Figure 1: structure of fiber optic cable

Fiber Optic Cable Types

Fiber optic cable types can be commonly divided into single mode and multimode optical fiber. With a diameter of 8.3 to 10 microns, single mode cable is a single stand of glass fiber, which has one mode of transmission. Single mode fiber has a relatively narrower diameter, through which only one mode will propagate typically 1310 or 1550nm. Although carrying higher bandwidth than multimode fiber, it requires a light source with a narrower spectral width. Multimode cable has a little bit bigger diameter, with a common diameters in the 50-to-100 micron range for the light carry component. Then how do we distinguish the single mode and multimode fibers?

Core diameter

The main difference between the multimode and single mode fibers is that the former has a larger diameter (usually the core diameter of the 50 or 62µm), and the typical single mode fiber has the core diameter of 8 and 10µm. The cladding diameter of both is 125µm.

single mode and multimode cable

Figure 2: single mode and multimode optical fiber

Light source

Both lasers and LED are usually used as light sources. The laser source is much more expensive than the LED light source, because its light can be precisely controlled and has higher power. The light produced by the LED light source is more dispersed (many modes of light), and these light sources are mostly used in multimode optical fiber jumpers. Besides, the laser source which produces near single mode light is usually used in single mode optical fiber jumpers.

Bandwidth

Because multimode fiber has larger core size than single mode fiber, it supports multiple transmission modes. In addition, like multimode fiber, the single mode fiber also presents mode dispersion caused by multiple spatial modes, but the mode dispersion of the single mode fiber is less than that of the multimode fiber. For these reasons, the single mode optical fiber has a wider bandwidth than the multimode optical fiber.

The color of the jacket

According to the TIA-598C standard, for non military purposes, single mode optical fiber adopts yellow outer jacket, and multimode optical fiber adopts orange or aqua outer jacket.

Mode dispersion

Multimode fiber has higher pulse expansion rate than single mode fiber, which limits the information transmission capacity of multimode optical fiber.

Fiber Optic Cable Advantages and Disadvantages

As we all know, at present, the application of optical fiber in communication can be seen everywhere. What are fiber optic cable advantages and disadvantages?

Advantages of Optical Fiber Cable:
  • Greater Bandwidth – Besides with immunity to electromagnetic interference, fiber optic cables have a much greater bandwidth and are much thinner and lighter than metal cables.
  • Larger Capacity – As the most secure medium available for carrying sensitive data, fiber optic cables have larger capacity and greater tensile strength than copper.
  • Lower Power Loss – An optical fiber offers low power loss, which allows for longer transmission distances.
  • Lower Cost – The raw materials for glass are plentiful, unlike copper which means glass can be made more cheaply than copper.
Disadvantages of Optical Fiber Cable:
  • Difficult to Splice – The optical fibers are difficult to splice, and there are loss of the light in the fiber due to scattering. They have limited physical arc of cables.
  • High Price to Install – The optical fibers are more expensive to install, and they have to be installed by the specialists.
  • Can’t Be Curved – Besides, the fiber optic cables can’t be curved, because the fibers can be broken or have transmission losses when wrapped around curves of only a few centimeters radius.

Fiber optic cable has both advantages and disadvantages. However, in the long run, optical fiber will replace copper. Nowadays, widely used, fiber optic cable becomes more popular than before. FS.COM, as the pioneer of optics supplier, provides all kinds of high-quality and reasonable-price optical fiber cables for your option.

Fiber Optic Cable: Storage & Handling Tips

The prevalence of fiber optic cable has become a trend which is embraced globally, since optical fiber offers unsurpassed advantages. Fiber optic cables are sensitive to excessive pulling, bending, twisting, crushing and other impact forces, for any such damage may alter the fiber property and may pose threats to its performance. So, optical cable should be stored and handled in an appropriate way. This article offers recommendations for proper storage and handling of fiber optic cable.

Fiber Optic Cable Storage

Fiber optic cable can be basically categorized into indoor fiber optic cable and outdoor fiber optic cable. Indoor cables are used exclusively within buildings whereas outdoor cables are employed in outside plant applications. Here are some factors to consider for indoor and outdoor storage.

Indoor Fiber Optic Cable Storage Recommendations
  • Always keep the reel tag that comes with the cable. There is vital information on the tag which indicates the cable description, attenuation, bandwidth and cable length. All these are valid identification of the fiber optic cable for future traceability.
  • Store fiber optic cable reels standing on both flanges, or held through center. Never store a cable reel sitting on one flange surface, which will result in possible future cable damage when unwinding.

indoor optical fiber storage

  • Once rewind the fiber optic cable to another reel, the diameter of the new reel shall be compatible with the minimum bending radius of the cable. And the original cable label details should be copied to the new reel.
  • In no circumstances shall any indoor cable boxes or reels be stored outside or in a harsh environment. Instead, indoor cables should be stored in a dry and UV protected location, such as a room or container.
  • Choose a site for storage with no risk of excessive humidity, falling objects, chemical spills (oil, grease,etc.) open flames or excessive heat. Elements like moisture and other contamination should also be considered when picking storage location.
Outdoor Fiber Optic Cable Storage Recommendations

Requirements listed below are applicable to both outdoor and indoor/outdoor fiber optic cables. Ends of the cables shall be sealed during storage.

  • All fiber optic cable reels including part used should be stored upright. Always store the reel in areas with flat firm surfaces. And use appropriate devices to secure reels to prevent reel movement during storage.
  • Avoid storage areas that are susceptible to flooding, or that could damage the cable, such as sharp, uneven terrain.
  • When the cable reel is too heavy to lift manually, it must be moved upright by lifting the cable with a forklift or reel mover. Never drop a cable reel from any height during transportation or use.
  • When unloading from a vehicle, use either the tail-lift / elevator (if fitted) or a suitable mechanical aid such as a forklift truck. Never let reels drop from the vehicle to the ground.

outdoor fiber optic cable storage

  • Before de-reeling cable, the reel should be visually inspected for possible damage caused during storage.
Considerations for Handling Fiber Optic Cable

Fiber optic cable is prone to damages due to improper handling and such damages can degrade the cable performance. Therefore the following suggestions may be useful to handle fiber optic cable properly.

1. Store the cable drums in an upright position, resting it vertically on cable flange edge not in the horizontal position. The flanges of reels shall not be interleaved, and reels must not be lifted by their flanges.

proper handling fiber optic cable

2. The rolling of the drum in the direction of the arrow decreases the chance for the cable to loosen its wind on the drum. However, you should notice that when pulling the fiber optic cable off the drum to install the cable, the arrow will point in the opposite direction to the rotation of the drum. (see the picture below).

proper handling fiber optic cable

3. When moving or handling the drum by a forklift, one should operate it in a proper manner to avoid any damage to fiber optic cable. The fork should not have any direct contact with the cable jacket.

handling fiber optic cable with forklift

4. While removing fiber optic cable from the drum. It is essential to avoid any reverse bending or twisting that may ultimately deteriorate fiber performance.

proper handling optical fiber

5. Always grounding optical fiber in figure 8 configuration, which allows for pulling of cable in both directions from a central location. It is necessary to protect the figure 8 coil form passers by. The figure 8 coil should be at least 10M by 5M. So what if the longer cable is required to be unreeled? The overwhelming weight of the coil may damage the cable at the bottom. In this case, try to spread the cable out in several figure 8 coils.

fiber optic figure 8 configuration

Conclusion

Proper storage and handling of fiber optic cable help to decreas chances for accidental damages, yet increases longevity of fiber optic cable. This article simply offers a recommended guideline for optical fiber storage and handling, while it is always wise to consult a professional for your unique application.