Fiber Optics: The Speed of Light Internet

How does a YouTube video get from a server in London to your phone in New York in 0.05 seconds? It travels under the ocean. Not on a wire. On a beam of light.

Total Internal Reflection

A Fiber Optic cable is a strand of glass as thin as a hair.

• We shoot a Laser down the middle.
• The glass is wrapped in “Cladding” (a mirror-like layer).
• The light bounces off the walls, zigzagging down the pipe for miles without losing brightness.

Why Not Copper?

Copper wires use Electrons.

• Electrons have resistance (Heat).
• Signal degrades after 100 meters. Light uses Photons.
• No resistance.
• Can travel 50 miles without a booster.

Miniature Fiber: TOF Sensors

Robots use this same tech in Time of Flight (ToF) distance sensors (like the REV 2M Sensor).

• Shoot a laser pulse.
• Measure how long it takes to bounce back.
• Distance = (Speed of Light * Time) / 2. We use the constant speed of the universe to measure exactly how far we are from the wall to park perfectly.