Name: The hidden network that makes the internet possible - Sajan Saini
Uploaded: 2020-03-20T16:32:18.000Z
Duration: 5 min 20 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

a team of Japanese and Danish researchers set a world record,

that’s 10,000 hours of high-def video—

over a fifty-kilometer cable, in a second.

It was a souped-up version  of fiber optics—

long-distance communications  between cities and countries

with metal wires limiting data rates  and power lost as wasted heat.

engineers mastered a far superior method of transmission.

glass can be carefully melted and  drawn into flexible fiber strands,

hundreds of kilometers long  and no thicker than human hair.

these strands carry pulses of light,  representing digital data.

But how does light travel within glass,  rather than just pass through it?

The trick lies in a phenomenon known  as total internal reflection.

lensmakers and scientists have  known that light bends

when it passes between air and  materials like water or glass.

When a ray of light inside glass hits its  surface at a steep angle,

it refracts, or bends  as it exits into air.

But if the ray travels at a shallow angle,

it’ll bend so far that it stays trapped,

something normally transparent to light can instead hide it from the world.

fiber optic signals barely degrade  over great distances—

Today, a single optical fiber carries many wavelengths of light,

And a fiber optic cable contains hundreds  of these fiber strands.

Over a million kilometers of cable  crisscross our ocean floors

that’s enough to wind around the  Equator nearly thirty times.

which has allowed the internet to evolve into a planetary computer.

our mobile work and play rely on legions  of overworked computer servers,

warehoused in gigantic data centers  flung across the world.

The vast majority of internet traffic  shuttles around inside data centers,

where thousands of servers are connected  by traditional electrical cables.

Half of their running power  is wasted as heat.

Meanwhile, wireless bandwidth demand  steadily marches on,

and the gigahertz signals used in our  mobile devices

It seems fiber optics has been too good for its own good,

fueling overly-ambitious cloud and mobile computing expectations.

But a related technology, integrated  photonics, has come to the rescue.

Light can be guided not  only in optical fibers,

Silicon wires don’t guide light as well as fiber.

all the devices in a hundred kilometer  fiber optic network

down to tiny photonic chips that plug into servers

and convert their electrical signals  to optical and back.

These electricity-to-light chips allow for wasteful electrical cables in data centers

to be swapped out for  power-efficient fiber.

Photonic chips can help break open  wireless bandwidth limitations, too.

Researchers are working to replace mobile gigahertz signals

they get absorbed by moisture in the air,

With tiny wireless-to-fiber photonic  transmitter chips

terahertz signals can be relayed over  long-range distances.

optical fiber, and make hyperfast  wireless connectivity a reality.

serving as a steady companion while we explored and settled the physical world.

Now, we’ve saddled light with information and redirected it

to run along a fiber optic superhighway—

with many different integrated  photonic exits—

to build an even more expansive,  virtual world.