Conectronica Revista Maganize industrial de electronica

Nowadays, the optical fiber cable use is a completed fact. The optical fiber cables respond to the exigencies and necessary requirements for the transport of great volumes of data. As much in lines of great route as communications between buildings and it even enters plants of the same, the optical fiber use is the best solution to the needs of the present networks.

In all the countries the multieven mesh wirings of copper by optical fiber cables are being replaced, since a cable with 8 optical fibers, so large rather smaller than the used ones habitually, can support the same communications that 60 cables of 1800 pairs of copper or 4 coaxial cables of 8 tubes, all this with one distances between repeaters much greater. Besides the bandwidth available in optical fiber, this element offers a series of advantages against the conventional wire nets such as immunity to the noise and interferences, multiplexación of signals, deficiency of electrical signals, weight and reduced dimensions and compatibility with the digital technology. The installation of this type of networks requires a specific equipación with which to be able to work the diverse elements available in the network. For the “union” of different optical fiber cables we can use two solutions following the needs and requirements:

System of joint by fusion

The family of fusioners Corning OptiSplice offers the possibility of fiber union by means of three systems different from fusion, as they are the system COMBAT (Injection and detection of light), CDS (detection of nucleus) and L-Pas (alignment of profiles of the fiber). The fusion process consists of the fiber union by means of a voltaic arc that “founds” the fiber glass obtaining the union of the different densidades from the cable, obtaining levels of attenuation in all the cases inferiors to 0,05dB.

LID System: This system allows the fusion through power measures. A light monomode (1300nm) is injected in the nucleus of a fiber by means of the bender of the left (emitting) and received on the other fiber in the bender of the right (receiving) Controlling the level of reception of light during the fusion we secured the optimal point of transmission in each one of the realised fusions System CDS: With this system we secured a fast prealignment of fibers. Fiber-viewpoint-105-3Un small electrical arc illuminates fibers so that the fusionadora realises a digital photography of the same, being able to detect and to analyze the nucleus of both fibers. The fusion will be realised by means of the alignment and confrontation of these nuclei, eliminating the possible existing eccentricities in cables.

System L-PAS: This system analyzes the profiles of the fiber

and it uses the correlation method to calculate the exact positioning of fibers, to control the prealignment with great exactitude and to detectacualquier shade or flaw throughout all the fiber open pie. System of mechanical joint Camsplice The Camsplice is a system of mechanical joint for fibers monomode and multimode, express and easy to use. Its main characteristic is the eccentric closing (Cam) that fixes fibers introduced without needing adhesive. Along with a glass groove of high precision in the form of V, this mechanism it forms a method of patented positioning that guarantees a very exact positioning of fibers.

With this system we secured attenuations of joint of the order of 0.05 dB. Once realised the installation of the optical fiber cable the completion becomes necessary of fibers in elements that facilitate their later conexionado one. Following the place of completion of fibers (distributing closet, box mural, optical equipment, PTRO…) we will be able to use diverse applications:

Completion in pigtail

A pigtail is an optical fiber cable with a connector assembled in factory in one of its ends, that will go connected to the corresponding system of distribution. The end that is without conectorizar will be the one that we unite to the completion of the incoming fiber cable. We will have to prepare both cables until letting to the fiber open pie in 125 µm to realise the fusion of union between both fibers, to protect the joint once realised (protective crimpado termocontraible or of) and to place it in its corresponding tray of joint. With this system we obtain a completion of the line with low attenuations and it allows a easy distribution us and I patch of fibers following the application to use. The market has a great variety of hardware where to be able to realise these completions (boxes murals, closets of distribution, subracks….) securing to a great capacity of transmission and repar- to of information in reduced spaces.

Like in the fiber joints, for the final conectorización, Corning offers the possibility of a mechanical conectorización by means of prepolished connectors. This is possible by means of the patented system Unicam®. The connector takes inserted an end of fiber in férrula, with polished final in factory. The Unicam connector contains in its interior a mechanical joint that will make the alignment and confrontation of the incoming fiber with the end of fiber premade inside the connector.

The assembly is extremely fast and simple and it allows the possibility of finishing the fiber us in diverse connectors standard to very low price. Optical fiber connectors The control of the surface of the connector is key to assure the reliability the network. The radius of curvature, apex offset and undercat of the fiber are other three parameters critics who in the medium and long term affect the operation of the connectors, reason why these parameters are supervised closely during the assembled process of.

Once installed cables, two parameters acquire vital importance: Losses of insertion: Resulting power loss to insert the connector in network. Losses of return: Signal level that returns to the source due to the reflections. The election of the polished type of of the connector (PC, APC.SPC, UPC) also influences in great way as much in the losses of return like in the losses of insertion. The general use of cords includes the interconnection of the cable of F.O of external plant with the opto-electronic equipment and/or the crossed connection of segments of the plant of the F.O cable. Measuring equipment After installing, to modify or to repair an optical fiber system, the measures and the test are of extreme importance to support a uniform operation and satisfac thorium of the network. The results of the measures indicate the quality of the network in numbers, show errors of the system and clarify the causes of the failures, especially when provider products have been used different. The main parameters of measurement of a F.O network are: - Attenuation of the network. - Absolute Level of the system. - Sensitivity of the receiver. - Total Bandwidth of the system.

The OTDR are used to graphically show the state of the fiber and to measure the respective loss of signal. The main virtue is that they allow to the location of events in the line such as joints, connections, possible failures of installation or defective materials These equipment works under the principle of the measurement of return of optical relaxation. It sends a pulse of light throughout the fiber and measures the retroesparcimineto or reflected light. It is the most versatile instrument within measuring equipment for F.O. The OV1000 is reflectómetro designed compact and modular optician for tests, testeos, documentation and measures in fiber networks of local area (LAN), to carrier, CATV and FTTx. Diverse combinations of wavelengths (850, 1300, 1310, 1490 1550 and 1625 nm) and dynamic ranges exist. This model of OTDR is of easy handling and extreme precision, with a resolution of 0.001 attenuation of dB, 128000 points of measurement for hi-res, three ways of testeo (automatic, advanced and groups), internal memory for 1500 plans, autonomy of 8 hours, slight weight, 10/100 Mb/s Ethernet cat. 5 RJ45, touch screen, easy handling of software for creation of professional information, including bidirectional analysis and function of fast impression. Its advanced design allows to reduce the died zone of the measurement to a distance among 1 and 4,5m us.

A light source and a measurer of power are basic parts within the equipación of any technician. With these equipment we obtain the measurement of the total losses of the line of communication. The light source acts like emitter from one of the completions of the fiber, emitting to a certain power. The power measurer is in the other end of the line, gathering the light emitted by the emitter. This way, by means of mathematical calculations, it measures and it shows the total losseses to us of the line. Range Corning the product offers the possibility to us of acquiring these equipment in several versions. We can own the light source and the measurer of power in two off-carriage equipment, emitting and receiving in different points of the network, or obtain a measurer of power with light source integrated in a single equipment, reason why we emitted and we received in the same place and with the same equipment. This family of equipment facilitates the work, since they own detection of automatic wavelength, eliminating possible errors by the incorrect adjustment between emitter and receiver. The equipment with two can be acquired, three and four wavelengths.

The active fiber identifier is an auxiliary tool of easy handling for the installation and maintenance of optical fiber systems. They detect of safe form the signals of the optical fiber and indicate its direction of transmission without interrupting the operation of the network. The direction of the signal and the type of signal (continuous, pulsating or none) are through the luminous indicators. It can additionally have an integrated measurer of power that at the same time measures and indicates the relative power of fibers. They work with a technology of nonintrusive detection, reason why the network suffers no damage neither during nor after the verification. Due to anchísimo spectrum of possibilities offered in the distribution as much in materials as in instrumentation, Rextel Private Networks in accordance with makes its available an equipment of engineering specialized in the study of the needs of each client and/or installation, integrating solutions the requirements demanded in each case, since as much the election of the materials to install as to have the suitable equipación it is the unique way to implement a communications network with the quality demanded in the present market.

Article preparation by the Technical Dept. of Rextel