🤖 AI Summary
Overview
This episode explores the groundbreaking development of fiber optics, the technology that revolutionized global communication and made the internet possible. It delves into the historical challenges of transmitting data over copper wires, the scientific breakthroughs that enabled the creation of low-loss glass fibers, and the engineering feats that turned this concept into a practical reality.
Notable Quotes
- The possibility of extremely high frequencies and accordingly vastly wider bands of frequencies appeared as a fabulous El Dorado, always beckoning us onward.
– A Bell Labs researcher on the potential of light for communication.
- Kao gave everyone a jolt. That was the first practical measurement which said, 'Hey, you're not just whistling Dixie.'
– A Bell Labs scientist on Charles Kao's groundbreaking work.
- Who knows what other forward thinkers will dream of in the future?
– Charles Kao, reflecting on the limitless potential of innovation.
📡 The Limitations of Copper Communication
- Early phone systems relied on copper wires, which transmitted sound by modulating electrical currents.
- To carry multiple calls on one line, phone companies used frequency bands, but higher frequencies caused signal loss due to eddy currents and resistance.
- By the 1960s, the telecom industry was struggling to meet the growing demand for phone calls, with copper wires reaching their physical limits.
💡 The Vision for Fiber Optics
- Glass fibers were initially dismissed as impractical due to extreme signal loss—1,000 decibels per kilometer.
- Charles Kao, an electrical engineer, challenged the prevailing belief that glass's high loss was intrinsic. He hypothesized that impurities in the glass, particularly metal ions like iron, were the primary cause.
- Kao's calculations showed that removing impurities could reduce loss to 20 decibels per kilometer, making fiber optics a viable alternative to copper.
🔬 Solving the Lossy Glass
Problem
- Kao identified two main causes of signal loss: scattering and absorption.
- Scattering occurs due to the disordered atomic structure of glass, which can be minimized by slow cooling to create a more uniform structure.
- Absorption was traced to impurities like iron, which absorb light at specific wavelengths. Removing these impurities was key to reducing loss.
- Kao's team measured the purest glass available, fused silica, and found it had a loss of less than five decibels per kilometer, proving his theory.
🔥 Engineering Breakthroughs in Fiber Manufacturing
- Robert Maurer and his team at Corning developed a method to create low-loss fibers using fused silica for the cladding and germanium-doped silica for the core.
- They overcame challenges in creating a perfect core-cladding structure by using a vacuum to evenly distribute glass soot inside a silica tube, which was then melted and collapsed into a solid preform.
- In 1970, they produced the first fiber with a loss of 17 decibels per kilometer, later improving it to just four decibels per kilometer with germanium doping.
🌐 The Internet Revolution
- By the late 1970s, fiber optic cables were being tested for telecommunications, and the first transatlantic fiber optic cable was installed in 1988.
- Fiber optics enabled digital communication, allowing multiple conversations, texts, images, and videos to be transmitted simultaneously as binary data.
- Today, over eight billion kilometers of fiber optic cables power the internet, with modern fibers achieving a loss of just 0.2 decibels per kilometer.
AI-generated content may not be accurate or complete and should not be relied upon as a sole source of truth.
📋 Video Description
Why making glass fibers to send signals was almost impossible. Sponsored by Saily - 🌎 Get an exclusive 15% discount on Saily data plans! Download Saily app go to https://saily.com/veritasium Use code veritasium at checkout ⛵
If you’re looking for a molecular modelling kit, try Snatoms, a kit I invented where the atoms snap together magnetically - https://ve42.co/SnatomsV
For the latest science news, and for an exclusive bonus Q&A with Sulli, the director of this video, sign up to the Veritasium newsletter - https://ve42.co/VeMail_FO
For early access to work in progress videos join our patreon https://ve42.co/VePatreon
▀▀▀
0:00 What are fiber optics?
2:02 Why Copper Phone Lines Had Limited Capacity
5:13 Trying To Go From Copper Communication To Glass
8:15 Why is glass so ‘lossy’?
11:29 Scattering and Absorption
16:00 How can you remove impurities in glass?
19:00 How They Make Fiber Optic Glass
26:47 The Technology that Made the Internet Possible
▀▀▀
Special thanks to the experts and collaborators who made this video possible:
Dr. Donald Keck
Prof. Vincent Chan
Sir David Payne
Dr. Nikola Alic
Jim Hayes
Jeff Hecht, whose book City of Light: The Story of Fiber Optics was an invaluable resource for this video (explore his work at https://www.jeffhecht.com).
Diffraction Limited, who made the fiber kits we used and some additional simulations that were critical to our understanding (https://www.youtube.com/@DiffractionLimited)
Trulala CANDY Chef (https://www.youtube.com/@TrulalaCANDYChef)
Additional thanks to:
ROSENDAHL NEXTROM for providing animations and fiber manufacturing 3D assets: (https://rosendahlnextrom.com/fiber/)
Bay Area Glass Institute for hosting our team. (https://bagi.org/)
Prysmian for giving us a guided tour of their fiber manufacturing plant, and our two on screen experts:
Sujeet Rao, Operational Excellence Fiber Director and Jon Fitz, Technical Sales Support Sr. Manager.
▀▀▀
References: https://ve42.co/FiberRefs
Note: The skin effect explanation is simplified. The full analysis involves the eddy currents' own magnetic fields, which induce further currents, and so on. Here’s an article on the same: https://ve42.co/SkinEffectDerivation
▀▀▀
Special thanks to our Patreon supporters:
Adam Foreman, Albert Wenger, Alex Porter, Alexander Tamas, André Powell, Anton Ragin, Balkrishna Heroor, Bertrand Serlet, Blake Byers, Bruce, Bryan Ackermann, Chris Brewer, Data Don, Dave Kircher, David Johnston, David Tseng, EJ Alexandra, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, Hayden Christensen, Hong Thai Le, Ibby Hadeed, Jeromy Johnson, Juan Benet, Kelcey Steele, Kyi, Lee Redden, Marinus Kuivenhoven, Mark Heising, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Parsee Health, Patreon mp22, Paul Peijzel, Robson, Sam Lutfi, Shalva Bukia, Sinan Taifour, Steven, Sweet_Nemo, Tair Aurmont, Tj Steyn, Ubiquity Ventures, Vahe Andonians, wolfee
▀▀▀
Credits
Writers: Sulli Yost, Henry van Dyck
Producer and Director: Sulli Yost
Presenter: Henry van Dyck
Editors: George Reynolds, Trenton Oliver and Axel Oliver
Assistant Editor: James Stuart
Illustrators: Jakub Misiek, Raphael Aubry, Thomas Brizard and Emma Wright
Animators: Aleksandrs Loginovs, Alex Drakoulis, Andrew Neet, Andrew Wernette, Domonkos Józsa, Emma Wright, Fabio Albertelli, Rokas Viksraitis and Sulli Yost
Researchers: Aakash Singh Bagga, Sophia Rose, Callum Cuttle and Gabe Strong
Camera Operators: Sulli Yost, Aaron Zhizhin, Emilia Gyles and Jesse Chandler
Thumbnail Designers: Abdallah Rabah, Daniel Ellacott
Production Team: Anna Milkovic, Glen Griffiths, Jess Bishop-Laggett, Matthew Cavanagh
Executive Producers: Derek Muller, Emilia Gyles and Henry van Dyck