Using a cable that was capable of sending signals few miles away was hard to imagine, a couple of decades back. Communication was geographically limited as conventional copper cables were incapable of high-speed and long-distance transmission. With the invention of fibre optic cables, the speed of communication rocketed. And, today transmission around the globe takes just a fraction of seconds. The use of fibre optical cables helped the rapid spread of internet technologies and web service and the world witnessed a drastic growth in various industries.
In the simplest form, fiber optics technology is using a glass or plastic thread to transfer data in the form of light waves. It replaced analogue data transmission with digital transmission. Fibre optical cables help with high-speed transmission as the interference is fractional compared to copper cables. Though light travels at a speed of 3,00,000 kms/second in a vacuum, it travels at two third speed of light in an optical fibre cable. A single tiny optical fibre thread is capable of carrying millions of telephone calls.
Fibre optics is transmitting data in the form of light. As we know the purpose of transmission cables is to distribute data between devices like computers, telephone or digital devices. Electronic devices are not capable of processing data in the form of light, instead, they process electronic signals. Therefore, in optical fibre technology, the electronic signals, created by devices are transferred into light waves and sends through fibre cables at a high-speed. The device at the other end transfers the light signals back into electronic signals to process them.
Laser beams are used to create the light waves. For example, if you want to transfer telephone calls through optical fibre cables, the device or telephone generates analogue signals. Analogue signals are transferred into digital signals. When each time a bit of data is transferred a laser light blinks at one end of the cable. This laser switch is capable to turn on and off billions of times each second, sending billions of bites every second. A device at the other end receives the blinking light and transfer them back into digital signals.
There are two types of optical fiber cables namely single-mode optical fiber and Multimode optical fibre. The term mode denotes the way light travels in the cable.
Singlemode fibre cable: Singlemode cables are those fibre threads that allow light beams to pass only on a straight line. These cables are so tiny that the diameter is only 5-10 microns. Cable, TV and telephone communication use singlemode fibre optical cables. Singlemode cables are capable of sending signals over long distances.
Multimode fibre cables: Multimode cables are 10 times larger than singlemode optical cables. In a multimode cable, multiple light waves can travel in different paths. Multimode cables are used for short-distance data transfer.