Basics of Fiber Optics

Fiber Optic Cable is a network cable containing strands of glass inside an insulated casing used for data networking and telecommunications over a long distance. The cable transmits information as light pulses inside the layers of glass to optimize speed and quality of signal. Proterial Cable America (PCA) manufactures fiber optic cables every day. 

What is the Fiber in Fiber Optics Cable? 

Cables can contain anywhere from one to hundreds of fibers, and each of those individual fibers is made up of three basic parts: The core, the cladding and the buffer layer. 

The Core

The core is the center of the fiber made up of glass that light signal transmissions travel within. 

The Cladding

The cladding is a glass layer that covers the core and serves as a barrier that keeps the light inside it. 

The Buffer Layer 

This is the outer packaging of the fiber. It is typically plastic and serves as the protective layer outside of the fiber.  

How do Fiber Optic Cables Work? 

Data is transmitted as light pulses which travel through the glass core of the fiber. The cladding layer reflects the light so that we achieve total internal reflection (TIR) to avoid signal loss. In other words, the two glass layers of the fiber work together to cause the light to travel through the cable delivering information from one location to another. 

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Are There Different Types of Optical Fiber? 

The two main types of fiber optics are—Singlemode fiber and Multimode fiber. Multimode and Singlemode refer to the number of light waves transmitted on the fiber. 

Single Mode Fiber Optic Cables

This type of fiber uses a narrower core, so the light only has room for one path. Because of that, it can travel longer distances without delivering corrupted information. A laser is used as the light source for singlemode, which means it has a longer range but gets hotter and is more expensive. It also has a higher bandwidth than Multimode.

Multimode Fiber Optic Cables

This type of fiber has a larger core and has room for light to take multiple paths simultaneously, which means the signal is more likely to cause dispersion, leading to issues like interference and signal loss. Multimode uses a Vertical Cavity Surface-Emitting Laser (VCSEL) as a light source, which means it can’t travel as far but uses less heat and is cheaper. For this reason, multimode applications tend to be shorter than singlemode fibers. 


What is a Fiber Optic Cable? 
After the fibers are manufactured they need to be protected so the cable stays safe during installation and from the environment afterwards. That way they are reliable for use. After the fibers are assembled, the cable is wound with aramid yarn (also used in bulletproof vests and often referred to by the DuPont trade name Kevlar) to pull the cable and prevent kinking. Then some cables add an armor layer to further strengthen and protect them. In fact, some cables include a layer of wire to further increase their strength. Finally, the tough outer layer of the cable is called the jacket which protects the cable core from the environment and mechanical stresses. 

At PCA, we manufacture tight-buffer cables and loose tube cables. 

Tight Buffer Cables 

Cables that have a thick plastic coating around each individual fiber are called tight buffer cables. PCA manufactures several types of tight buffered cables. 

  • Interconnect Cables are composed of one to 12 fibers, are highly flexible and thus are ideal for patch panel cross connects. 
  • Distribution Cables have several tight-buffered fibers surrounded by strength members and a jacket. They are common in premise installations. 
  • Breakout Cables are more robust cables containing a subunit jacket around every tight buffered fiber, which can be broken out and terminated at different places. 

Loose Tube Cables 

The other type of cable manufactured at PCA are loose tube cables. These cables contain fibers tightly packed inside a tube with no gel, and are then cabled together, wrapped in the Kevlar layer before adding the final jacket. These cables are the most common in installations where a high fiber density is needed, and are ideal for MTP/MPO connectors. 

Advantages of Fiber Optic Cables 

There are two major advantages of fiber optic cables—They usually provide increased data rate capacity and can transmit data over longer distances. 

In addition, fiber optic cables require little maintenance, are more robust from a magnetic interference perspective and are both stronger and lighter than copper cables. 

Are Fiber Optic Cables Better than Copper Cables? 

The quick answer is—it depends. There are multiple reasons to choose fiber optic cables over copper, but that doesn’t mean it’s universally the best option. 

Having said that, fiber optics have higher data rate capabilities since these cables are operating in the Terahertz range bandwidth as opposed to Mega or Gigahertz range in copper cables. In addition, fiber optics use light, which can obviously move very quickly, so signal boosters are less often necessary. Fiber Optics are more secure as well, and can’t be tapped into like copper cables can. Finally, fiber optics avoid most interference, where copper cables are more susceptible to the issue. 

Copper cabling has its advantages as well: it is easier to install, more likely to be compatible with existing infrastructure, less fragile and cheaper.

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Interested in Fiber Optic Cables? 

Proterial Cable America is a reliable and trustworthy fiber optic cable manufacturer. We can accommodate whatever your fiber optic needs are, and look forward to helping you. Click here to see what Fiber Cables we offer.