#1 Fiber Game Changer: It Uses Light to Send Data
Internet that’s as fast as light? Absolutely. You just have to turn to fiber optic cables. Instead of using an electrical current like traditional copper telephone wires, fiber cables literally carry data using beams of light shot out by lasers. Let’s discuss.
How does light carry data?
Have you ever watched a movie where someone uses a mirror or flashlight to send a message with Morse code? Well, fiber optic internet cables use light to carry messages in much the same way, except the light travels inside a thin glass fiber rather than being broadcast out into the world.
Technically, here’s how it works: Any data transmitted over the internet is encoded in binary—a numbering system with just 0s and 1s. For example, in the most popular version of binary notation, “A” is 01000001 while “B” is 01000010 and “Z” is 01011010.
Any long article or complex file is made up of tens of thousands of 0s and 1s that can be transmitted incredibly quickly with the flashes of light sent through fiber optic cables by lasers. When there’s a pulse of light, it’s a 1; when there’s no pulse of light, it’s a 0. The computers running things at either end are able to handle hundreds of thousands of pulses per second, which is why they can transfer such large files so quickly.
It’s important to note, copper cables also use binary to transmit data. However, instead of flashes of light, the voltage of the cable is changed to transfer information.
How do fiber optic cables work?
Okay, so now that you understand how something like this website can be converted into light, let’s look at how the actual fiber optics work to transmit it hundreds or thousands of miles, and even across oceans.
Fiber optic cables are made up of three parts: a thin inner “core,” a slightly thicker “cladding” and a protective external “buffer” layer that keeps the inner layers safe from the external environment.
The core and the cladding work together to transmit data using a principle called “total internal reflection.” Both layers are made from different kinds of ultra-pure glass. The glass in the core has a higher “refractive index” than the glass in the cladding, which means light travels slightly more slowly through the core than it does through the cladding. (This has some interesting effects on light that passes from one medium to the other, which you can see for yourself when you put your arm in a swimming pool: It looks like it’s bending because the water has a higher refractive index than the air.) Because of the light’s shallow angle as it’s sent through a fiber optic light cable, however, each beam gets trapped in the core. When it hits the cladding, it’s reflected back in such a way that it continues its journey, bouncing along from side wall to side wall.
In theory, with perfect glass you could make a fiber optic line that could carry light indefinitely. Unfortunately, the real world gets in the way. With even the best fiber optic cables, there’s some signal “attenuation” or loss. This means there are practical limits to how far you can send data before you need a “repeater,” which resends the signal, or an “amplifier,” which boosts the existing signal.
Why is glass better than copper wires?
Fiber optic cables have a few big advantages over copper wires. They’re more durable, suffer from much less attenuation, so need less infrastructure, and, best of all, can transmit a huge amount more information at faster speeds—which is why fiber connections offer such fast internet speeds.
Let’s just look at one way fiber allows for bigger bandwidth. Because copper cables use electricity to transmit data, they’re vulnerable to electromagnetic interference—including from other nearby cables. This means copper cables have to be tightly insulated and, ideally, kept away from other cables.
But because fiber optics uses light to transmit data, there’s no fear of electromagnetic interference. This means dozens of fiber optic lines can be bundled together into thick cables to transmit thousands of gigabits per second. This is how Google has a cable with a bandwidth of 60 terabytes of data per second that connects the U.S. and Japan.
Why isn’t everything fiber yet?
You now may be wondering, if fiber optics is so much better, then why are copper cables still used?
Well, we’re going to let you in on a little secret: The entire internet is already running on fiber optics. All the big cables that transmit information between your internet service provider and data centers around the world are fiber. When you send a Facebook message to someone on a different continent, it crosses the ocean using a fiber optic cable. Even if you use 5G data with your iPhone, the information is only traveling wirelessly until it gets to the cell tower—then it’s on the fiber optic internet.
Copper cables are only used for the last few miles to connect homes and businesses that don’t yet have a fiber connection. DSL service, for example, piggybacks on existing telephone connections, so it’s already available across most of the country, while fiber-to-the-home connections are still rolling out.
This means, though, if you’re fortunate enough to live in a location where you can get a gigabit fiber connection, you should go for it. It will guarantee you the fastest upload and download speeds and reliability. Plus, fiber is the future.