Communication is widely use in nowadays. From past to present lots of communication systems has been used and day by day newer systems and subsystems are entering to the world, through the thirsty of Communication engineers, new way to transport information is explored, which very effective and efficient than others. One of them is Fiber Optics.
There are much of ways to transmit information, such as Radio waves, UV, FM, AM, Micro waves and such waves. But the Fiber Optic technology use totally different way to transmit information. That is "Light Rays", which is very easy to transmit, using simple method of lights. That is reflection rules.
Those things are learn in the O/L grades. But the nature is the applicability of those simple things in the utilized way. That's why the Fiber optics technology came out to the communication systems.
Communicate with lights are common for many years. In older days, used fire Communication, then reflecting lights using mirrors, also head lights in our vehicles. So the Fiber Optics technology is built as a result of this lighting communication.
Characteristics of Fiber Optics
Transmitting in the Fiber Optics is bit complicated from normal communication system. First of all information source get the information that need to transmit. And then "Electrical transmitter" transmits information to the "Optical source". From the Optical source, information goes to the "Optical Fiber". Then the Information would get to the destination where the "Optical detector" placed on. From that it goes to Electrical receiver. Finally to the receiver..
This is placed in between infrared and ultraviolet in the Electromagnetic spectrum, which the range is 1.7um - 0.8um. That's a very narrow range compared to other electromagnetic waves.
It uses Total internal reflection to transmit signals.
When it look into a cross-over, inner most is the core, middle is jacket and outer is cladding.
Fiber optics cannot takes 90Ëš bends. Then the signal is go out from the total internal reflection. So when it need to have a bend, it have take a smooth liitle bends.
Fibers make out of glasses or plastics.
Maintaining is hard to done.
Power consumption is very low compared to the copper cables.
Connector types of Fiber optics
Connecting a Fibers is not a easy task as connecting copper cables. It's a micro scale task which is can be done by only specialists on combining them. There is so many types of connectors and connecting methods that's very high level methods. Some are really hard to be done, but its going to be the best ways for connecting Fiber optics together.
From the sea of connector types, few of them are presented in very simple.
Butt joint connector
From these Connector types in Fiber optics, most commonly using type is Butt joint Connector. Because of the easiness of connecting method that use to connect. Also there are lots of various type connectors under the Butt joint connector, that all cannot mention in this chapter. Those are primarily developed for use with single mode Fibers. But for some cases, multimode is also uses in this.
This connecting type is the simplest connecting design in Fiber Optics. It uses metal plugs known as ferrules, it have a accurately drilled in their faces with central holes where the bond is needed. Two ferrules sleeves are placed with the help of accurate machines and adjust the alignment of them for butt joining. It's essential to keep the fiber face to be smooth and perpendicular to the fiber cable.
This alignment of ferrule is mainly depend on the ferrule hole, which is fiber is inserted. By using watch jewel, it helps to synchronies the two fibers together. So then the error of not synchronized area is reduced to 2-6um.
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Figure 3.1.1 :Ferrule connector
This is also much similar to Ferrule type Connector, but in here it uses jumper cable for some applications in the Bell system is the biconical plug connector. The way of connecting this is, either plugs are transfer molded directly or cast around the fiber using a silica loaded resin to connect tidy to within 5um. After inserting plugs it need to clean and polish the two faces of fibers. Then the biconical plugs are inserted with centered to molded. And then silica resin pads are placed over the fiber end faces to match together.
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Figure 3.1.2 :Biconical connector
Ceramic Capillary connector
This is also much similar to the ferrule type connector. Difference is much accurate ferrule alignment is used in the ceramic capillary connector. Special feature of this is, using the ceramic capillary on tip of the ferrule connector. So then it gives a accurate positioning of the two fiber together. This connector is also used in the coupling of single mode fibers.
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Figure 3.1.3 : Ceramic capillary connector
Double Eccentric connector
This is not a fixed type sleeve, but can adjustable. Can alignment closer to the fiber axes. This is consists with two plugs with eccentric cylinders. So the fiber optic is mounted by outer cylinder as in the Figure 3.1.4. So the it's always possible to rotate around the cylinder axes for adjustments. Those adjustments are done for both plugs using either a inspection microscope or a peak optical adjustment. Then the plugs are locked to take as a permanent mount. Also in here it uses a fluid within the connectors to losses the error of the faces. This design is very unique to single mode fibers and also for the small core diameter fibers.
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Figure 3.1.4 : Double eccentric connector
Triple ball connector
This is developed by British telecom, which is a very unique design that consists with triple balls. In here the fiber optic is gripped by the three tungsten spheres and two sets of tungsten spheres were together with 60Ëš. It helps to butt joint the connector and keep the alignment in place.
Single Mode Connector
However the Ceramic capillary and double eccentric connectors have been developed by the single mode connectors. But in previously Single mode fibers are not been designed to that purpose.
It consists of pair of fiber plugs and sleeves with ball bearing inside the cylinder. Ball bearing helps to keep alignment accurately and smoothly. Also it allow o rotate plugs, so it's more flexible to align fibers touch together.
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Figure 3.1.6 : Single mode connector
Compared to the Single mode fibers, few of the multiple connectors are developed to communication systems. The way of connecting multiple connectors are, there is a multiple type sleeve that joint large number of moulded together. It's actually like bunch of ribbons together. The technique used in here is multiple groove splicing methods for ribbon cable.
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Figure 3.1.7 : Multiple connector
Expanded beam connectors
This is the majorly 2nd type of connectors that is totally differing from Butt joint connector. This connector type consisting two lenses that bonds the Optic beam together by expanding one end of fiber beam and direct to the other lens. Two lenses are connected to the faces of the fiber optic.
It's not easy to tolerate small kind of beams to interconnect accurately. So the it's so much useful to use this type of connecter to bond them together with the minimum tolerance as much as 0.7dB.
This is very useful for sort of fiber optics that cannot be align easily or difficult to achieve in connecting together. Also it's so much useful for multi fibers. Tapers are also been used with fibers to worth the expanded beam connectors.
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Figure 3.2 :Expanded beam onnector
SC is stand for Subscriber connector. It's commonly use push/pull type connector that is developed by NTT.
For the newer communication systems SC is widely used. Also this is used in single mode connector. As these are low cost, more durability and accurate, it causes to uses in widely. The most special of is connector is that it have a very low tolerance in it, which is 0.25dB.
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Figure 3.3 : SC connector
ST is stands for Straight tip connector. In the network applications, this is the most commonly use type connector, uses for both short and long distance networks. This is integrated with twist lock coupling. This connector type has a shadow of ferrule type and in the ST also it has spring loaded. ST connectors has two types, which are ST and ST-II. Those are keyed and spring loaded
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Figure 3.4 : ST connector
MT-RJ stands for 'Mechanical Transfer Registered Jack'. This is very popular for small form fibers. Special feature of this connector type is, it's utilized using two of MT-RJ the work of RJ45 cable. And also this is half size of SC type connector design. The MT-RJ is commonly use in connecting purposes. As it's mentioned before specially to Ethernet connections.
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Figure 3.5 : MT-RJ connector
MTP connector is high performance of MPO connectors. MPO stands for 'Multi Fibber push on'. These connectors have more than one fiber inside and it has increased the optimization of the cable.
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Figure 3.6 : MTP connector
This connector gives high performance other than the SC and ST connectors. This content with ferrule ceramic and low loss of signal. Applications of din connectors are LAN, MAN, WAN, industry, medical and sensors.
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