This document provides an overview of fiber optic telecommunication. It introduces fiber optic components used in telecommunication systems, including different types of optical fibers, light sources, detectors, couplers, and wavelength division multiplexers. It discusses how fiber optic systems work and their advantages over traditional metallic systems, namely higher bandwidth and lower signal loss over longer distances. The document aims to give readers a basic understanding of fiber optic communication technologies and their growing role in modern telecommunication infrastructure.