- All right, buds, you got to check this out.
This map represents 750,000 miles of fiber optic cables
that are currently running under our oceans.
And when I think of the internet, I think of 5G,
I think of Starlink satellites, I think of WiFi,
but I never think about what's inside all of these cables.
And how the future of the internet,
buds, it relies on these hair thin,
super durable strands of glass.
- [Reporter 1] The making of glass for mirrors,
especially telescope mirrors...
- [Reporter 2] Optical fiber will play a central role
in helping to modernize the country's telecommunication.
- Glass is 5,000 year old material
that has always had a rich history with technology,
and without it, you wouldn't be watching
this video right now.
- All modern means of communication is entirely enabled
by glass and hundreds and hundreds of millions of miles
of this stuff made every year.
I'm John Ballato.
I'm a professor of material science and engineering
at Clemson university.
I'm also the Sirrine Endowed Chair of Optical Fiber.
[Becca] Buds, he knows a lot about glass.
- It never gets old.
Since the first installation of fiber networks
back in the eighties, we, the industry,
have made 5 billion kilometers of optical fiber.
We don't think about living in a wired world,
we think about living in a wireless world.
It's not strange to ask where's the fiber in all that.
So what really happens is,
you have your tablet, you have your smartphone,
you're downloading, uploading things.
That information is being sent wirelessly
using microwaves to a local router.
- [Becca] And in most cases, it travels as electrons
from the router to a centralized hub.
- And then out the back of that,
that information is all converted into light,
gets propagated around the world
over a fiber made out of glass.
This is a piece of optical fiber.
This is telecommunication's quality.
It is a hair thin piece of glass,
and you will not break this.
- [Becca] But to get to that super-durable piece of glass,
well, it starts out looking like this.
That's a preform in John's hands, and it's 20 years old,
but the preform used today can be up to two stories tall
and much, much wider.
Within that preform is a core that is pure glass,
surrounded by a glass cladding
with a lower refractive index.
This allows light to travel easily through the core
without scattering or fading.
The preforms are then pulled into hair-thin strands of glass
and then coated with a protective plastic housing.
- 99% of the material that goes into the glass optical fiber
is, by and large, the same as it was 50 years ago.
We've just gotten better at making more of it.
- [Becca] Now, let's talk about what's actually
moving through that glass.
As far back as the telegram,
telecommunication has relied on a pattern of pulses
similar to Morse code to relay information.
So, pulses are sent over great distances,
and then on the opposite end,
they're decoded to relay information,
but we haven't always used glass to do that.
The much more expensive, much heavier copper
was once the standard for telephones,
cable TV, and the early stages of the internet.
And copper is still used in a lot of connections today,
but there are two main limitations with that:
one, electrons long copper,
they don't travel as quickly as light,
and two, electrons cannot pass through one another.
So a single copper wire, it just isn't as efficient
in sending data back and forth.
Light, on the other hand, can move far more freely
through a single strand of glass.
And crucially, light can carry more data
because it has a higher frequency,
and frequency just means the amount of wave cycles
that occur within a certain amount of time.
Here's how that works, and buds, I'm totally about to go
Verge Science on you, but stick with me.
(printing working)
This piece of paper represents an amount of time,
like, fractions of a second.
Radio waves from a typical radio in your car
are measured in megahertz.
So for our example, there are 112 size font.
I can fit about one alphabet in this amount of time.
Then 5G can reach tens of gigahertz,
a much higher frequency, think like size 18 font.
Now I can fit about 39 alphabets onto this page,
and then light waves and fiber optics,
they can have frequencies in the hundreds of terahertz,
about size two font here.
In that same amount of time, I'm sending way more data,
about 1,276 alphabets in our analogy here.
So if we want to speed up our connection,
we need to figure out how to encode as much information
within the frequency of light as possible.
(upbeat music)
- The reason we're doing research in optical fiber
is that more (mumbles) the demand for usage has exploded.
That expansion is driving capacity by 60% per year.
And it's been that way for 30 years,
and has no expectation of stopping.
- [Becca] Tod Sizer leads a research lab
at Nokia Bell Labs, and last March,
a researcher from his team set a new company record
when they transmitted 1.52 terabits per second of data
over 80 kilometers of single-mode fiber.
- It's about 1.5 million YouTube videos at once.
That amount of information is higher
than what is available today.
We fully expect that in two or three years,
my business will have it as a product,
but for right now, it was our search experiment.
We have to do that in order to meet that 60% per year curve.
- Are we going to need to update
that material at some point?
Is there a limit to the current fibers that we have?
- So there is a limit.
The limit was actually defined 70 years ago
in this very building by a mathematician
called Claude Shannon.
And what Claude Shannon said is that, in any channel,
whether it's a fiber optic connection
or a wireless connection,
there is a fundamental limit on how much
information you can send over that.
We've been following a curve towards getting
towards Shannon's limit for the past decade.
Now we've effectively reached it,
and so, we need think differently.
(suspenseful music)
- Vivian, what am I looking at right now?
It's beautiful, but what is it?
- What you are looking at is optical transmitter.
What the transmitter do is to try to modulate the light
and to encode information on the light.
- [Becca] This is Vivian Chen.
She's a scientist here at Nokia Bell Labs,
and she's currently showing us how our data
is converted into light and then passed through a fiber.
- If you observe, it has a fiber coming in
and a fiber goes out.
And the fiber coming in connects to a laser.
And then it got modulated through this device.
It changes the power of the light
and output of the modulator,
typically going into your transmission fiber,
and then you send into that fiber link
that is laid on the bottom of the ocean.
And on the other side of the ocean,
you will have the optical receiver
that basically try to do the reverse of this.
Communication between machines,
it's like communication between people.
What we have is a language system.
So at the very beginning,
what we do is switch the light on and off,
and the receiver detect the light is on,
it recognize it as the information bit one.
And when the light is out, it's information bit zero.
And nowadays, you can do more than switching it on and off.
You can switch it half on and half off,
and you can make more levels, many, many levels,
in between the full on and the full off.
- In today's optical fibers, we carry, at the same time,
several hundred colors of light,
several hundred 1.6 terabytes signals.
And wouldn't it be nice if it wasn't just a hundred
but maybe a thousand colors you could send?
That would help us for four or five years.
Another way of thinking about it is to go
into fiber that has no glass in the middle.
It's called hollow core.
It has actually air in the middle
that might allow us to go faster as well.
- The future of the internet is going to physically
need miles and miles of fiber optic cables
and huge infrastructure changes.
A few weeks ago, the Biden administration
released an infrastructure plan
that aimed for universal high-speed internet.
And it referred to broadband as the new electricity
in terms of everyday need.
It's unclear exactly how that allocated money
will be distributed, but telecom companies
are hoping it will help with fiber optic upgrades.
Only about a third of nationwide coverage is on fiber now,
and some major cities, they have even less than that.
Manufacturers such as Corning and Sumitomo,
they'll have to produce huge amounts
of near-perfect fiber optic cable
before telecom companies can even install them.
And as all of these changes happen,
it's important to remember one thing.
- You could not do anything over the internet
if not for glass, even if you take a step back
and think about the gorilla glass on your phone.
Historically, people think in terms of material ages:
the stone age, the bronze age.
There's certainly something to be said about the glass age.
Glass is important today as it was 5,000 years ago,
just in a different enabling way.
- Buds, thank you so much for joining me on this journey.
It has been truly a labor of love,
and I hope you guys enjoyed watching it
as much as I enjoyed making it.
Stay tuned to the Verge Science channel
because next week, they're going to have
something real special for you as well.
And, yeah, thank you guys.
We'll see you in the next one.