Optical fibers show an example of how scientific knowledge translates into technological progress, ultimately making life easier for the average person. For several years, fiber optics has been associated with communication means for transmitting electrical signals. Thin filaments the size of a human hair can be used to transmit a wide range of signals that are required to operate a telephone, Internet connection, TV, etc. Of course, due to its high performance, fiber optics have found use not only in domestic needs.
Optical signal transmission technology
In itself, the use of optical fiber as a signal translator is only part of the disclosed knowledge that is being explored in the scientific section of fiber optics. Specialists in this area are studying the transmission of information and the propagation of light, and in one context, united by light guides. The latter are used both as distributors of light and as transmitters of information. By the way, modern trends in the development of laser technologies are based on LEDs. In this case, another question is more interesting - what phenomenon is the basis of fiber optics? This phenomenoninternal reflection of (total) electromagnetic radiation at the interface between dielectrics having different refractive indices. Moreover, the information carrier is not an electromagnetic signal at all, but a coded light flux. To understand the degree of superiority of fiber optic cables over traditional metal cables, it is worth once again referring to their bandwidth. The already mentioned fiber thread, whose thickness is no more than 0.5 mm, is capable of transmitting an amount of information that ordinary copper wiring will only serve with a thickness of 50 mm.
Fibre-optic fabrication methods
There are two main methods by which optical fiber can be manufactured. It is a technique of extrusion 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. A preform is a preform that is in a structure designed for drawing threads. By modern standards, preforms can be up to several tens of meters high. Outwardly, this is a glass rod with a diameter of about 10 cm, from which the core of the thread is melted. During the manufacturing process, the core, together with the mixture for the fibers, is heated to high temperatures, after which the filaments 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 the fiber optics will be used, the material forIt can be pre-treated with coatings that provide chemical and physical protection. As for the filament blends themselves, they usually include materials such as polyimide, acrylate and silicone.
Fiber design features
The central part of the thread is the core - the very core of the fiber, which will spread light during operation. The core is characterized by increased light refractive indices, which is achieved by using glass doping with modification by special additives. For example, typical refractive components like a dopant are used for silica fibers. In turn, the shell performs several tasks, the main of which is the direct physical protection of the core. This part also provides the effect of refraction, but with a minimum coefficient. The boundary between the two materials forms a light guide structure that does not allow the bulk of the light to escape from the core. It is also worth noting that the basics of fiber optics refer the material to varieties of light guides. 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 materials similar in structure, including doped silicon oxide. This base makes it possible to produce flexible and long fibers that differ inand high mechanical strength. Plastic-fiber optics are made from polymers and, as already noted, cannot 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 affordability of plastic fibers keeps the demand for this material in the directions focused on the household segment. As for fluoride optical materials, their basis is based on fluorozirconate 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 their use, for example, in the medical industry.
Fiber Measuring Equipment
The most common equipment used in optical fiber kits are sensors and Bragg gratings. Fiber optic sensors are devices designed to fix certain values that characterize the state of the material at the moment. For example, different sensors can detect mechanical stress, temperature, vibration, pressure, and other quantities. The Bragg grating in its function is closer to the optical characteristics. It fixes an aperiodic refraction disturbance in the fiber core. This measurement allows you to determine how efficient fiber optics is in transmitting a signal under specific conditions. Also, experts use opticalreflectometer that registers dissipation and resistance.
Fiber-optic amplifiers and lasers
This is the most advanced product developed on the basis of fiber optics technology. Unlike other types of lasers, the use of optical filaments makes it possible to create compact and at the same time efficient devices. In particular, fiber optics technology has made it possible to replace classical laser devices with the following advantages:
- Efficiency of heat sink.
- Increased output radiation.
- Effective pumping.
- High reliability and stability of the laser.
- Low weight equipment.
In turn, amplifiers, depending on the type, can also be used in home network lines, increasing the performance of the main fiber line. However, the scope of fiber operation is worth considering in more detail.
What is fiber optics used for?
There are several areas in which fiber optic materials are used. This is the sphere of domestic use, telecommunications equipment and computer equipment, as well as highly specialized niches, including certain areas of medicine. For each of these segments, special fiber optics are 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 for laser equipment and expensivemedical devices use high quality quartz fibers, also provided with additional modifiers.
Application of optical fiber in medicine
Such fibers can be used in medical equipment and instruments. Standard technology suggests the possibility of introducing a special device based on refracted light fibers, which can transmit a signal to an external television camera already in the body organ itself. Fiber optics is used in medicine and as a lighting material. Devices equipped with fiber modules make it possible to painlessly illuminate the cavities of the stomach, nasopharynx, etc.
Use of optical fiber in computer equipment
Perhaps this is the most common niche in which optical fiber has found its place. Today, communication lines between individual devices that transmit information can no longer do without it. Of course, this applies to those areas in which it is impossible or impractical to use wireless connections, which are also actively replacing cables as such. For example, the largest telecommunications companies are laying interregional backbone networks that use fiber optics. The use of such channels for connecting peripheral equipment and ordinary consumers of telecommunications services allows you to optimize the financial costs of maintaining the network infrastructure, and also increases the efficiency of data transmission itself.
Disadvantages of fiber
Unfortunately, optical threads are not without weaknesses. Although the maintenance of such wiring is cheaper, not to mention the absence 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 in some alloys, which are toxic to humans. This mainly applies to the highest quality glass models, not plastic ones.
Production of optical fiber in Russia
As part of the import substitution program in 2015, the Optical Fiber Systems plant was opened in Mordovia. This is the only enterprise in the Russian Federation, which is currently trying to meet the needs of domestic consumers in optical fiber to the extent possible. Until 2015, the Russian industry was also engaged in the manufacture of fiber optic materials, but only within the framework of individual targeted projects. The same situation persists to some extent today. If a certain company needs fiber optics and its use in medicine or in the field of telecommunications will be financially justified, then there are many factories that are ready to work on such special orders on an individual basis. However, in the near future, only the Mordovian plant will be producing serial production of the same fiber optic cables. Moreover, it is not yet able to supply the market in accordance with the volume of demand. A significant proportion of products are still purchased from the US and Japan. And even domestic products are produced on importedraw materials.
Conclusion
Fiber optic products have been forming as a market segment for about 15-20 years. Over the years, the consumer has been able to appreciate the merits of new cables, but progress does not stand still. With the improvement of technical and physical qualities, the areas of application of the material are also expanding. The latest fiber based on nanotechnology, in particular, is actively used in the oil and gas industry and the defense industry. In turn, nonlinear fiber optics is currently developing only conceptual, but very promising areas of technology. Among them are compression laser pulses, optical solitons, ultrashort optical radiation, etc. Obviously, in addition to theoretical research with possible discoveries and within the framework of purely scientific knowledge, new developments will also make it possible to make new offers to consumers of different levels on the market.
