Fiber optics and its application

Optical fibers show an example of how scientific knowledge translates into technological progress, ultimately easing the life of an ordinary person. For a number of years, communication means for transmitting electrical signals have been associated with fiber optics. Thin threads the size of a human hair can be used to transmit a wide range of signals that are required for the operation of the phone, Internet connection, TV, etc. Of course, due to high operational capabilities, fiber optics has found application not only in domestic needs.

Technology of signal transmission through optical fiber

In itself, the use of optical fiber as a signal translator is only part of the knowledge that is being explored in the scientific section of fiber optics. Specialists in this area are engaged in studying the transmission of information and the propagation of light, and in one context, combined with light guides. The latter are used both as light distributors and as transmitters of information. By the way, LEDs are based on modern directions of development of laser technologies. In this case, another question is more interesting: what phenomenon is the basis of fiber optics? This phenomenon of internal reflection of (full) electromagnetic radiation within the boundaries of dielectrics having different refractive indices. Moreover, the carrier of information is not an electromagnetic signal, but an encoded light flux. In order to understand the degree of superiority of fiber optic cables in front of traditional metal cables, it is worthwhile once again to turn to their bandwidth. The already mentioned fiber thread, whose thickness is no more than 0.5 mm, is able to transmit the amount of information that ordinary copper wiring will serve only at a thickness of 50 mm.

Methods of manufacturing optical fibers

There are two main methods by which an optical fiber can be manufactured. This is an extrusion technique and melting using preforms. The first technology makes it possible to obtain low-quality material based on plastics, so today it is practically not used. The second method is considered the main and most effective. Preform - a blank, located in a structure designed for drawing threads. According to modern standards, preforms can have a height of up to several tens of meters. Outwardly it is a glass rod about 10 cm in diameter, from which the core of the filament is melted. During the manufacturing process, the core together with the fiber mixture is heated to high temperatures, after which the threads are formed. The length of the resulting material can reach several kilometers, although the diameter remains unchanged - it is controlled by automated regulators. Depending on where fiber optics will be used, the material for it can be preliminarily treated with coatings that provide chemical and physical protection. As for the blends for the yarns, they usually include materials such as polyimide, acrylate and silicone.

Design features of fiber

The central part of the filament is the core - the very core of the fiber, which will spread the light in the process of exploitation. The core is characterized by high refractive index of light, which is achieved by using glass doping with modification with special additives. For example, quartz fibers use typical refractive components like dopant. In turn, the shell performs several tasks, the main of which is the immediate physical protection of the core. This part also provides an effect of refraction, but with a minimum coefficient. The boundary between the two materials forms a lightguide structure that does not allow the main volume of light to go beyond the core. It is also worth noting that the fundamentals of fiber optics classify the material as a type of fiber. To be more precise, we are talking about dielectric waveguides that transmit light signals.

Varieties of optical fibers

The most common are quartz, plastic and fluoride fibers. Quartz filaments are based on oxide melts or structurally similar materials, among them doped silicon oxide. This base makes it possible to produce flexible and long fibers, which are also characterized by high mechanical strength. Fiber-optic optics is made of polymers and, as already noted, can not provide high performance. In particular, such threads have a high percentage of data loss, which limits their use in demanding areas. On the other hand, the price availability of plastic fibers keeps demand for this material in directions oriented to the household segment. As for fluoride optical materials, their basis is based on fluorocyranate and fluoroaluminate glasses. These are quite modern and technological solutions for providing optical communication, but the content of heavy metals in the structure also does not allow them to be used, for example, in the medical industry.

Measuring equipment for optical fibers

The most common equipment that is used in sets with optical fiber are sensors and Bragg gratings. Fiber optic sensors are devices designed to fix certain values that characterize the state of the material at a given moment. For example, different sensors can detect mechanical stress, temperature, vibration, pressure and other quantities. The Bragg grating in its function is more approximated to the optical characteristics. It fixes an aperiodic disturbance of refraction in the core of the optical fiber. This measurement allows you to determine how much fiber optics is effective in translating the signal under specific conditions. Also, specialists use an optical reflectometer that records the scatter and resistance.

Fiber-optic amplifiers and lasers

This is the most progressive product, which is developed on the basis of fiber optics technology. Unlike other types of lasers, the use of optical fibers allows the creation of compact and at the same time efficient devices. In particular, the technology of fiber optics made it possible to replace classical laser devices due to the following advantages:

• The efficiency of the thermal tap.
• Increased output radiation.
• Effective pumping.
• High reliability and stability of laser operation.
• A small mass of equipment.

In turn, amplifiers, depending on the type, can be used in home network lines, increasing the performance of the main fiber line. However, the scope of operation of optical fibers should be considered in more detail.

What is fiber optics used for?

There are several directions in which fiber-optic materials are involved. This sphere of domestic use, telecommunications equipment and computer technology, as well as niche niches, among which are separate areas of medicine. For each of these segments, special fiber optics is produced. Application as a typical means of transmitting a TV or Internet signal, for example, is limited to cheap plastic models of medium quality. But high-quality quartz fibers are used for laser equipment and expensive medical devices, which are also provided with additional modifiers.

Application of optical fibers in medicine

Such fibers can be used in medical equipment and instruments. The standard technology assumes the possibility of introducing a special apparatus on refracted light fibers, which already in the body organ can transmit a signal to an external television camera. Fiber optics in medicine and as a lighting material are used. Apparatus equipped with fiber modules allows painless illumination of the stomach cavity, nasopharynx, etc.

Application of optical fibers in computer equipment

Perhaps this is the most common niche in which the fiber optic has found its place. Without it, communication lines between individual devices that transmit information can no longer be dispensed with today. Of course, this applies to those areas in which it is impossible or inappropriate to use wireless connections, which also actively displace cables as such. For example, the largest telecommunications companies are laying interregional backbone networks, which involve fiber optics. The use of such channels for communication of peripheral equipment and ordinary consumers of telecommunications services allows to optimize financial costs for servicing the network infrastructure, and also improves the efficiency of data transmission itself.

Disadvantages of fiber

Unfortunately, optical threads can not do without weak points. Although the maintenance of such wiring is cheaper, not to mention the lack of the need for frequent updates, the cost of the material itself is much higher than the same metal counterparts. In addition, fiber optics and its use in medicine is extremely limited due to the content of lead and zirconium impurities, which are toxic to humans, in individual alloys. Basically, this applies to the most high-quality glass models, and not plastic ones.

Manufacture of optical fibers in Russia

In the framework of the import substitution program in 2015, the factory "Optical-fiber systems" was opened in Mordovia. This is the only enterprise in the Russian Federation, which at the moment, as far as possible, tries to fill the needs of domestic consumers in fiber. Until 2015, Russian industry was also engaged in manufacturing of fiber-optic materials, but only within the framework of separate target projects. The same situation is still in part today. If a certain company needs fiber optics and its use in medicine or telecommunications is financially justified, then there are many factories ready to work on such special orders individually. However, in the near future, only the Mordovian plant will be running serial production of the same fiber-optic cables. Moreover, so far it is unable to supply the market in accordance with the volume of demand. A significant portion of the product is still purchased in the US and Japan. And even domestic products are produced on imported raw materials.

Conclusion

Fiber-optic products are formed as a segment of the market for about 15-20 years. During these years, the consumer was able to appreciate the advantages of new cables, but progress does not stand still. As the technical and physical qualities increase, the fields of application of the material also expand. The newest fiber on the basis of nanotechnology, in particular, is actively used in the oil and gas industry and the defense complex. In turn, nonlinear fiber optics is developing only conceptual, but very promising directions of technology. Compression laser pulses, optical solitons, ultrashort optical radiation, etc. can be distinguished among them. Obviously, in addition to theoretical studies with possible discoveries and within the framework of strictly scientific knowledge, new developments will allow the market to make new proposals to consumers of different levels.