How Does Fiber Optic Internet Work?

how does fiber optic internet work

While you’ve probably heard of fiber internet, you may not understand the specifics. Don’t feel singled out — it’s a complex process. So, how does fiber optic internet work? Here’s an easy-to-understand breakdown.

The Fundamentals of Fiber Optic Technology

The most fundamental part of fiber optic technology is the fiber optic strands — thin strings of glass — carrying data from one end of a cable to the other. Unlike traditional copper cables, they use light instead of electrical signals.

Since fiber optic strands are so thin, you can fit dozens — sometimes even thousands — inside one cable. They’re usually 125 microns thick, but sizes vary. For perspective, the average human hair is about 100 microns thick. 

Fiber optic manufacturers bundle the strands together and place them in a brightly-colored polymer sheath, which makes a cable. The protective outer layer comprises flexible materials, allowing it to bend at various degrees.

Fiber optic technology transmits information using pulses of light, moving about 69% as fast as the speed of light. However, they have the potential to be even faster in a vacuum. This feature makes them much quicker than traditional copper cables. 

The Different Types of Fiber Optic Cables

Although technically dozens of fiber optic cables exist, there are two main types. The first is single-mode fiber, which is thin. It can only carry one mode of light — meaning the path light follows — with a high bandwidth for faster data transmission.

The second is multimode fiber. Its core diameter is about 50 microns thick — single-mode fiber is only 5-10 microns thick, for comparison — because it carries multiple light modes. It has low bandwidth, so it’s less expensive to install.

How Can Light Be Used to Carry Information? 

A technique called amplitude key shifting lets light carry information. Depending on dimness and brightness, light can represent binary digits — the ones and zeroes computers use to process data. A device at the end of a cable translates those signals, making them understandable. 

In binary, a capital “B” is represented as 01000010. The amplitude key shifting technique would turn those ones and zeroes into an off-on-off-off-off-off-on-off pattern. Once the signal reaches the end of the cable, it gets translated back into a “B” — this is how light carries information. 

Data encoded into light can only be transferred from one end of a cable to the other because of a principle called total internal reflection. As the signal travels down the glass core, it constantly bounces off the cladding — the material surrounding the core — forcing it to keep moving.

The Advantages of a Fiber Internet Connection

Fiber internet is better than other options like DSL, satellite or cable. Here’s why you should consider a fiber internet connection.

  1. Reliability 

Fiber internet isn’t affected by weather or obstacles because the cables lie underground, meaning you’ll have nearly 100% reliability even during power outages. How does fiber optic internet work in a blackout? It transmits light instead of electricity.

  1. Speed

Where DSL and cable get a few hundred megabits per second (Mbps), fiber usually gets 1,000 Mbps. Some tech demonstrations have shown it can reach 1 petabit per second, equal to 1,000,000,000 Mbps. The maximum you can get for home use is 10,000 Mbps.

  1. Stability

Like power outages, fiber internet is immune to signal interference because it doesn’t rely on electricity. Plus, since it uses ultra-clear glass free of impurities, nothing can stop or delay light signals from transmitting data.

How Does Fiber Optic Internet Work Better?

Fiber internet works better than its alternatives because it uses light signals. DSL and cable use copper strands prone to interference and downtime. The story is the same for satellites — they’re thousands of miles away, so obstacles and bad weather affect them.

While fiber internet is pricey — digging up miles of ground to lay cables is labor intensive — it performs much better and offers faster speeds than alternatives. In most cases, it even provides equal upload and download speeds.

Should You Switch to Fiber Optic Internet?

Fiber internet is a good choice if it’s in your area because it’s reliable and offers high bandwidth. That being said, its availability is limited. How does fiber optic internet work in residential areas? Generally, a telecommunications company has to pay to lay the cable. Since it’s expensive, they usually only install it in or around cities.