Fiber Optics: How It Works 

In today’s world, fiber optic cables are one of the most popular means of data transmission. A few decades ago, traveling terabytes of information through such “glass fiber optic cables” would have seemed like real magic. Modern man faces this technology daily. High-speed Internet, digital television, mobile communication – all this is possible thanks to fiber optic cable.

Fibre optic cables continue to be actively used in the most high-tech areas.

The History Of Optical Communication

Using light to transmit information was learned quite a long time ago. We can remember the optical telegraph, which appeared in France in the XVIII century. Then it was able to surprise with its incredible speed – to transmit information for 200 kilometers in just fifteen minutes.

In 1824, the first optical telegraph line began its work in Russia, and a little later, the St. Petersburg-Warsaw communication line with a length of 1200 km was opened; at that time, it was a world record in terms of length. Sending an “optical” telegram can be compared to the modern Internet, except for the speed – it took about 20 minutes to transmit 45 conventional signals from St. Petersburg to Warsaw.

Optical communication, in the modern sense, emerged in the 1950s, when it was learned to make thin double-layer fibers from unique transparent materials. The invention of lasers in the 1970s made it possible to build fiber-optic transmission lines.

A Conductor For Light: How Fiber Optics Works

Thus, light can transmit information, and people realized this centuries ago. At first, the primitive method worked only at a line-of-sight distance, and then fiber optics made it possible to transmit light over many thousands of kilometers and far from a straight path. But how is that possible? The key word in explaining this phenomenon is refraction. This is the basis of the principle of operation of optical fiber – light is repeatedly refracted, remaining inside. By analogy with electricity flowing along a metal wire, an optical fiber is sometimes called a “light guide.”

The light source in the cable becomes a laser. At the other end of the cable, the light awaits a receiving device that recodes it back into an electrical signal. This happens very quickly – the laser turns on and off several billion times a second, transmitting billions of bits of data. For comparison, the most popular for computer networks, an eight-core cable of four twisted pairs, carries up to 1,000 megabits per second. In contrast, single-core fibre optic cables carry three times that amount. Undoubtedly, speed is one of the main advantages of fiber optics. And no wonder since light is the fastest thing known in the universe.

The optical fiber is an incomplete transparent tube made of a unique material with glass properties. For this purpose, scientists began to use quartz glass. Despite the apparent fragility of glass, optical fiber has an exceptional flexibility. It can even be twisted into a ring – this will not affect the characteristics of the cable, and light will continue to “run” through it without any problems.

At The Speed Of Light: From Subway To Space

A new domestic quartz optical fiber with improved characteristics was presented.

This product has all the advantages of traditional fiber optics. In addition to being lightweight, easy to install, and fast, it is immune to electromagnetic interference – the light signal cannot be intercepted. This novelty also has a clear advantage over existing analogs – the core diameter increased to 100 microns instead of the typical 50 microns and 62.5 microns, and a unique gradient profile of the refractive index. This increases the reliability of the data network without loss of bandwidth.

The innovative fiber is primarily designed for cable systems operating in aggressive environmental conditions. For example, the development will be part of on-board cable systems – from subway trains to airplanes and spaceships.