Origins of Telecommunications | Harnessing the Power of Light to Communicate with Fiber Optics

With a laser, amplified light is created in an energized medium by reflecting light back and forth.

fiber optics phoneIn just the proverbial blink of an eye, telecommunications technology has evolved from smoke, light, and flag signals to blazing fast, real-time communications at nearly the speed of light.

Even within our own lifetimes, long distance telephone calls, for example, have improved dramatically.

The days of awkward delays while the audio signal traversed the globe are well behind us. In their place, we have fiber optic networks, among other technological marvels, and at the fraction of the cost.

Fiber Optics Explained

Fiber optic cables transport light pulses generated by lasers or light emitting diodes (LEDs). The cables themselves contain long, glass or plastic fiber strands. The core within each fiber strand is much more reflective than its surrounding materials, which continuously reflects the light pulses back into core where they continue their journey.

Not only are fiber optic cables able to transmit voice, images, and data at practically light speed, fiber optics offers several advantages over copper wires such as:

  • Much greater capacity at similar thicknesses. This means that a fiber optic cable offers much more bandwidth than a similarly sized copper cable. Ratings of up to 100 gbps are common with fiber optics.
  • There’s less interference than with traditional cables which means cables can be laid close to each other without the need for extensive shielding.
  • There’s also a reduced reliance on signal boosters because the light can travel much further before losing its strength.

Method of producing optical waveguide fibers

Early Experiments with Light in the 1800s

Fiber optics are not a new invention by any stretch of the imagination. In fact, we can trace the origins of fiber optics to the mid-1800s. Here’s a short timeline:

1840s — Two physicists (Daniel Collodon and Jacques Babinet) showed that light could be directed along jets of water, creating spectacular nighttime fountain displays.

1854 — Another physicist (John Tyndall) proved that light could be bent by shining a light into a stream of flowing water, which created an arc of light as the water flowed.

1800 — William Wheeler used reflective light pipes and an electric art lamp to direct light indoors.

1880 — The inventor of the telephone, Alexander Graham Bell, is also the inventor of the “photophore,” which was an optical telephone.

1888 — Two doctors in Vienna illuminated body cavities using bent glass rods.

1895 — Henry Saint-Rene, a French engineer, designed a system of bent glass rods used to guide television-like light images.

1898 — Another curved glass rod was put to use, this time as a dental illuminator invented by David Smith.

Light Innovations in the 1900s

As the century turned, ideas for using light evolved. The idea for using a series of transparent rods to transmit light images in television was patented in the 1920s. It took about a decade before am image was actually transmitted through optical fibers, however. Several competing patent applications for light imaging were submitted, and denied, over the years, followed by a cladded fiber system with reduced interference and crosstalk.

By the mid-1950s, the maser (microwave amplification by stimulated emission of radiation) and, a few years later, laser (light amplification by stimulated emission of radiation) were developed.

With a laser, amplified light is created in an energized medium by reflecting light back and forth. Laser technology improved with helium-neon gas lasers followed by synthetic pink ruby crystal lasers in 1960.

The next year, the concept for modern fiber optics consisting of thin glass fibers with tiny cores that could carry light was introduced by Elias Snitzer of American Optical. Snitzer’s glass fiber – laser demonstration had potential for medical applications, but due to excessive light loss, was not suitable for communications.

A paper published in 1964, by  Charles Kao and George Hockham, theorized that removing impurities would decrease light loss in glass fibers.

Finally, Corning Glass Works made a modern breakthrough for producing “optical waveguide fibers” with its combination of a refractive glass film and glass tube. This combination was drawn out to form a thin glass fiber with a solid cross-sectional area and a core that was formed from the glass film, and a cladding that was formed from the glass tube.

The resulting fibers were a huge improvement over copper wire, carrying roughly 65,000 times more information.

About a decade later, the standard currently still in use today for the manufacture of fiber optic cables was developed by Bell Laboratories. This process involves heating oxygen and chemical vapors to form a low-loss “ultra-transparent” glass.

Fiber optic links for telephone transmissions began moving out of the lab and into practice in the early to mid 1970s. In 1977 in Chicago, the first fiber optic phone system was installed.

By the mid-80s, the first nationwide, all-digital fiber optic network emerged, putting Sprint on the map. Long distance calling costs began to fall – and the audio was crystal clear. So clear, in fact, that Sprint used the phrase “you can hear a pin drop” in its advertising.

Innovations in fiber amplification were also being developed in the late 80s and early 90s, resulting in greater data capacity — up to 100 times more in the case of a built-in amplifier — and dramatically lower costs for long distance systems.

In the mid-90s, international fiber optic cables using optical amplifiers began to appear, transforming international telephone and data services dramatically. The Fiber Optic Link Around the Globe, for example, was a foundational step toward ushering in the era of high-speed Internet.

By the late 1990s, fiber optic cables carried about 80 percent of all international telephone traffic.

Fiber Optics Today

Today, fiber optics remain the preferred medium for telecommunications systems including domestic and international telephone, cell phone, teleconferencing systems as well as CATV, CCTV, and computer networking systems.

Not only does this technology allow for high capacity, high speed communications, it is also rugged and low-maintenance

https://www.aitelephone.com

=======================================

Sources:

“Fiber Optic Cables: What They Are and Why They’re Used.” 2017. Accessed September 12. https://www.lifewire.com/fiber-optic-cable-817874.

“History of Fiber Optics.” 2017. Accessed September 12. http://www.timbercon.com/history-of-fiber-optics/.

“History of Optical Fiber.” 2017. Accessed September 12. http://www.m2optics.com/blog/history-of-optical-fiber.

“How Fiber Optics Was Invented: A Timeline.” 2017. Accessed September 12. https://www.thoughtco.com/birth-of-fiber-optics-4091837.

“Sprint’s Pin Drop Commercial – The Retroist.” 2017. Accessed September 14. https://www.retroist.com/2014/11/18/sprints-pin-drop-commercial/.

“The FOA Reference For Fiber Optics – Networks.” 2017. Accessed September 14. http://www.thefoa.org/tech/ref/basic/nets.html.

“US3711262A – Google Patents.” 2017. Accessed September 12. https://patents.google.com/patent/US3711262A/en.