Optical fiber is a physical medium for transmitting information, usual in data and telecommunications networks, consisting of a thin glass or plastic filament, through which pulses of laser or LED light travel, in which the data to be transmitted.
Through the transmission of these light pulses, information can be sent and received at high speeds through a cable run, safe from electromagnetic interference and with speeds similar to those of radio. This makes fiber optics the most advanced cable transmission medium available.
The implementation of fiber optics is heir to centuries of research and experimentation on light and its properties, from ancient times when the Greeks communicated through the reflection of sunlight in small mirrors, the optical experiments of the Scientific Revolution, until the invention of optical telegraphy in 1792 by Claude Chappe, and the later work of the French physicists Jean-Daniel Colladon and Jacques Babinet, and the Irishman John Tyndall, all at the end of the 19th century.
The optical fiber as such would not enjoy the interest of the engineers until 1950, and in 1970 the first piece would be manufactured, using impurities of titanium in silica, by work of Robert Maurer, Donald Keck, Peter Schultz and Frank Zimar. The first transmission of information through this medium was made on April 22, 1977, in Long Beach, California, and in the 1980s, it was perfected. It began to be implemented on an international scale.
What is fiber optics for?
Fiber optics are ideal for cable telecommunications, allowing long-range and local computer networks to be established with minimal information loss along the way.
Its applications are diverse in this field, allowing the obtaining of network material, fiber optic sensors (for temperature, pressure or light levels), lighting material (particularly effective since it does not require proximity to the light source), and is also useful for decoration (there are Christmas trees made of fiber optics) or as a component of translucent concrete.
How does fiber optics work?
The principle of operation of optical fiber is that of Snell’s Law, which allows calculating the angle of refraction of light when passing from one medium to another with a different refractive index.
Thus, within the fiber, the light beams are trapped and propagating in the core, given the physical properties of the cladding and the appropriate angle of reflection, transporting the information sent to the destination. In the latter, it operates in a similar way to the telegraph.
Fiber optic characteristics
The optical fiber used today is made up of a plastic or glass (silicon and germanium oxide) core that has a high refractive index, covered with a similar plastic, but with a lower refractive index.
Thus, according to the mechanism of light propagation inside, the optical fiber can be of two types:
- Single-mode fiber. It allows the propagation of a single mode of light, by reducing the diameter of the fiber core, allowing information to be sent over long distances and at a good transfer rate.
- Multimodal fiber. It allows light beams to propagate in more than one way (more than a thousand different modes), which increases the margin of error and makes it not recommended for very long-distance connections.
Advantages of fiber optics
Optical fiber has the following advantages:
- It takes up little space. Given its small size, but it is extremely flexible, which facilitates its installation.
- It is light. Well, it weighs eight times less than a conventional cable.
- It presents great resistance. Both mechanical and thermal, and it resists well to corrosion.
- It is more ecological. Compared to the waste left by conventional wiring.
- Immune to electromagnetic interference. Given the nature of its components.
- Fast, efficient and safe. It is the best-known form of cable data transmission.
Disadvantages of fiber optics
The disadvantages of fiber optics point to the following:
- They are fragile since the glass inside is susceptible to breaking.
- It requires converters. To return the light energy to its informative sense.
- Splices are difficult, especially in rural areas.
- It does not transmit electrical energy. Therefore, it requires complex emitters and transporters, whose energy supply cannot be taken from the line itself.
- It ages in the presence of water, which limits its worldwide application.
- There are no optical memories.