Optical Time Domain Reflectometer Assessment of Attenuation in Fiber Optics Communication System

Abstract

Attenuation is an undesirable factor that weakens the strength of signal as it travels down fiber optics. Attenuation level in every fiber communication link must be kept at its tolerable range in order to maintain good signal transmission. When the level of attenuation in a link is higher than the acceptable tolerance value, the transmission suffers some setbacks such as loss of signal, freezing of signal etc. An optoelectronic device, Optical Time Domain Reflectometer (OTDR) was used in the measurement of attenuations in the single-mode fiber using the uni-directional technique. It is a convenient and powerful tool for rapidly assessing attenuation behavior in optical fibers. It combines a detector and laser source to provide an inside view of the fiber link described by a trace. The injected light pulse from the laser source is received at the detector. OTDR traces were produced in accordance with the light pulses received. From these traces, the attenuation levels for the different fiber cores were obtained. An average attenuation limit of 0.188 dB/km and average section loss of 0.3dB for 1550 nm wavelength window over the span length of 1597.35 m were achieved which are within the acceptable standard range of 0.20 dB/km to 0.30 dB/km.