Optical fibers provide an example of how scientific knowledge transforms into technological progress, ultimately making life easier for the average person. For several years, communication means for transmitting electrical signals have been associated with fiber optics. Thin strands the size of a human hair can be used to transmit a wide range of signals that are required for a telephone, Internet connection, TV, etc. Of course, due to its high operational capabilities, fiber optics have found application not only for domestic needs.
Fiber Optic Transmission Technology
The mere use of fiber as a signal translator is only part of the knowledge that is 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, combined by optical fibers. The latter are used both as light distributors and as information transmitters. 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 laid in the basis of fiber optics? This is the phenomenon of internal reflection of (total) electromagnetic radiation at the interface of dielectrics having different refractive indices. Moreover, the information carrier is not an electromagnetic signal at all, but a coded light stream. To understand the superiority of fiber optic cables over traditional metal cables, one should once again turn to their bandwidth. The already mentioned fiber thread, the thickness of which is not more than 0.5 mm, is capable of transmitting the amount of information that ordinary copper wiring will only service at a thickness of 50 mm.
Fiber Manufacturing Methods
There are two main methods by which optical fiber can be manufactured. This is a technique of extrusion and melting using preforms. The first technology allows 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 workpiece in a structure designed to draw threads. By modern standards, preforms can be up to several tens of meters high. Outwardly, it 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 fiber mixture, is heated to high temperatures, after which the filaments are formed. The length of the material obtained 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 pretreated with coatings that provide chemical and physical protection. As for the mixtures for threads themselves, they usually include materials such as polyimide, acrylate and silicone.
Optical Fiber Design Features
The central part of the thread is the core - the very core of the fiber, which will spread the light during operation. The core is characterized by increased refractive indices of light, which is achieved by using glass alloying with modification with special additives. For example, for quartz fibers, typical refractive components like dopant are used. In turn, the shell performs several tasks, the main of which is the direct physical protection of the core. This part also provides a refractive effect, 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 go beyond the core. It is also worth noting that the basics of fiber optics attribute the material to varieties of optical fibers. 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, including doped silica. This basis allows the production of flexible and long fibers, which are characterized by high mechanical strength. Plastic-fiber optics are made from polymers and, as already noted, cannot provide high performance. In particular, such threads have a large percentage of data loss, which limits their use in demanding areas. On the other hand, the affordability of plastic fibers retains the demand for this material in areas oriented towards the household segment. As for the fluoride optical materials, their base 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 them to be used, for example, in the medical industry.
Fiber Measuring Equipment
The most common equipment used in kits with optical fiber are sensors and Bragg gratings. Fiber optic sensors are devices designed to capture 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 disturbance of refraction in the core of the optical fiber. This measurement allows you to determine how effective fiber optics are when broadcasting a signal in specific conditions. Experts also use an optical reflectometer, which records the scattering and resistance.
Fiber Optic Amplifiers and Lasers
This is the most progressive product that is being developed based on fiber optics technology. Unlike other types of lasers, the use of optical fibers allows you to create compact and at the same time efficient devices. In particular, fiber optics technology has made it possible to replace classical laser devices due to the following advantages:
- Heat dissipation efficiency.
- Increased output radiation.
- Effective pumping.
- High reliability and stability of the laser.
- A small amount of 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 operation of optical fiber should be considered in more detail.
What is fiber optics used for?
There are several areas in which fiber optic materials are involved. This is the sphere of domestic use, telecommunications equipment and computer equipment, as well as highly specialized niches, among which there are certain areas of medicine. For each of these segments, special fiber optics are produced. The use 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 expensive medical devices they use high-quality quartz fibers, which are also provided with additional modifiers.
The use of fiber in medicine
Such fibers can be used in medical equipment and instruments. Standard technology suggests the possibility of introducing a special apparatus on refracted light fibers, which already in the body organ itself can transmit a signal to an external television camera. Fiber optics is used in medicine and as a lighting material. Devices equipped with fiber modules allow painlessly highlighting the cavity of the stomach, nasopharynx, etc.
The use of optical fiber in computer equipment
Perhaps this is the most common niche in which fiber has found its place. Today, communication lines between individual devices transmitting 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 also actively displace cables as such. For example, the largest telecommunication companies are laying interregional backbone networks that use fiber optics. The use of such channels for communication between peripheral equipment and ordinary consumers of telecommunication services allows us to optimize the financial costs of servicing the network infrastructure, and also increases the efficiency of data transmission itself.
Fiber Disadvantages
Unfortunately, optical fibers do not do without weak points. Although the content 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 in certain alloys that are toxic to humans. This mainly concerns the highest quality glass models, not plastic ones.
Optical fiber production in Russia
As part of the import substitution program, the Fiber-Optic Systems plant was opened in Mordovia in 2015. This is the only company in the Russian Federation, which at the moment, as far as possible, is trying to meet the needs of domestic consumers in optical fiber. Until 2015, the Russian industry was also engaged in the manufacture of fiber-optic materials, but only as part of individual targeted projects. The same situation is partially preserved today. If a certain company needs fiber optics and its use in medicine or in the field of telecommunication support will be financially justified, that is, many factories are ready to work on such special orders individually. However, in the near future, only the Mordovian factory will work with serial production of the same cables from fiber optic. Moreover, while he is not able to supply the market in accordance with the volume of demand. A significant proportion of products are still purchased in the United States and Japan. And even domestic products are produced on imported raw materials.
Conclusion
Fiber optic products have been forming as a market segment for about 15-20 years. Over the years, the consumer was able to appreciate the merits of the new cables, but progress does not stand still. As technical and physical qualities increase, the areas of application of the material expand. The latest nanotechnology-based fiber, in particular, is actively used in the oil and gas industry and the defense industry. In turn, nonlinear fiber optics is developing only conceptual, but very promising areas of technology. Among them, one can distinguish compression laser pulses, optical solitons, ultrashort optical radiation, etc. It is obvious that in addition to theoretical studies with possible discoveries and within the framework of purely scientific knowledge, new developments will also allow new offers to consumers at various levels on the market.