Optical amplifiers are essential in modern fiber-optic networks, boosting signal strength without electrical conversion. An illustration of the effective gainis given below. Note the presence of a gain peak around 1530nm and a semi-flat gain. Erbium-doped fiber amplifier (EDFA) is the most widely used fiber-optic amplifiers, mainly made of Erbium-doped fiber (EDF), pump light source, optical couplers, optical isolators, optical filters and other components. Typical fiber cables experience a loss of about 0. There are 2 types of optical amplifiers; an OFA (Optical Fiber Amplifier) and SOA (Semiconductor Optical Amplifier).