The Erbium Doped Fiber Amplifier (EDFA) has now replaced optoelectronic repeaters as the primary design option for extending the range and capacity of the World's fiber optic telecommunication systems. In a broader sense, optical amplifiers are the basis of all lasers. It is therefore essential that students of science and engineering have a broad appreciation of, and practical familiarity with, optical amplifiers in general, EDFAs in particular and their applications in lasers. To achieve these objectives, Strathclyde University in collaboration with OPTOSCI LTD. have developed an EDFA/Laser educator kit which enables students to experimentally investigate the gain and noise characteristics of an EDFA, including issues such as signal and pump saturation, gain efficiency, amplified spontaneous emission and optical beat noise. With a simple extension to the basic amplifier kit the students are able to construct an erbium doped fiber ring lasers and to investigate its power characteristics (threshold and slope efficiency) as a function of output coupling ratio and intra-cavity loss. The experimental objectives, design philosophies, hardware, experimental procedures and results will be examined in detail in this paper.