Comparative Analysis of Fiber Optic Voice Link Using Intensity Modulation in Commercially Available Optical Fibers

Communication is the method by which two persons can share any meaningful information with each other at an instant. It requires a sender who wants to communicate, message which is to be conveyed & receiver who receives this message at the receiver end. Now a days due to the advancements and technology, digital communication is receiving wide attention among researchers. Digital communication is achieved by sending digital messages in form of pulses 0 & 1 through modem. Modem is mediator to transfer the message which consists of both modulator & demodulator. The communication can only be possible with modulation .In this paper, the digital communication link is established using the fiber optic voice link technique which uses intensity modulation in different optical fibers such 1m step index, 1m graded index & 1m glass optical fibers. Intensity modulation is basically the modulation in which output power of the source varies in accordance with modulating signal. In FM optical communication system, even if an electrical base band signal is used to modulate the frequency of electrical carrier, it is still the parameter which works i.e. intensity of light wave varies with the electrical FM carrier. The purpose of this paper is to study the switched faults in fiber optic voice link in different fibers using intensity modulation with the help of ST-2502. The switched faults are basically used to find out the fault conditions in FM modulation system. Keywords— Intensity Modulation, Frequency Modulation, Fiber Optic Cables