Fiber optic cables can carry signals in a single direction. Data is sent from one end of the cable and received on the other end. Data signal is sent using a Light emitting Diode (LED) or by using lasers. In order to send and receives signals to complete the round, you need to have two strands of cables. Light signals are turned on and off in order to transmit data. Different types of fiber optic cables are available. The two types of cables usually used are as follows:
1) Single mode - A type of cable that has only a single strand of glass fiber with a thin diameter. The diameter of the core glass is approximately 8.3 to 10 micrometer. Only a single light signal can be transmitted through it. Single mode fiber is more resistant to signal attenuation than multimode fiber. Thus more information can be transmitted over long distances, increasing speed of transmission. Fiber optic cables that use lasers are known as single mode cable.
The advantage of single mode fiber optic cable is that data can be transmitted at higher speeds. Single mode fibers can also transmit data over longer distances as compared to multimode cables.
The disadvantage of single mode fibers are that only one signal can be transmitted through it. To transmit two signals you need two strands of fiber optic cables.
2) Multi mode - A type of cable that contains a glass fiber with a larger diameter. Multiple modes of light signals can be propagated through it. This is a 62.5/125 micrometer fiber cable. Light signals are transmitted into the fiber using different paths and wavelengths. Multi mode fiber transmits the data over short distances as the various modes tend to spread over long distances, resulting in attenuation. Fiber-optic cables the use LEDs are known as multimode cables.
The advantage of this type of cable is that you can transmit two or more signals using a single fiber. The disadvantage of this type of cable is that data cannot be transmitted over long distances using this cable. Since two or more signals are transmitted using one fiber, the transmission speed is less as compared to single mode fiber optic cables. Single mode fiber-optic cable that uses laser light has a capacity to cover a long distance with high transfer rates. To differentiate between a single mode and multimode fiber-optic cable is somehow a difficult task. Single mode and multi mode fiber can be differentiated depending on their core diameter. Multi mode fiber has larger core diameter as compared to single mode fiber. Multimode cables are used nowadays.
Source: http://factoidz.com
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