This paper is divided into four subsections: 1) LED Source Components, 2) Source Modulation Electronics, 3) Photodetector Components, and 4) Receiver Electronics. The important characteristics of LED source components are discussed, both qualitatively and quantitatively. Edge, dome, flat, Burrus, and miniature-lensed Burrus LED types are identified, and performance parameters available from each are comparatively tabularized. The source modulation electronics discussion is divided into analog and digital categories. Two practical linear IM driver configurations are presented (low and high frequency), and practical, digital low and high bit rate driver configurations are presented. The design considerations underlying each circuit are discussed. Solid-state optoelectronic detectors of interest in fiber optics communications fall into the two general categories of avalanching and nonavalanching (PN/PIN). Available performance in several key parameter areas is quantified for both types. The receiver electronic configuration discussion begins with examination of a general block diagram and brief description of each function. Focus is then concentrated on the transresistance preamplifier function, with the presentation and parameter comparison of four practical preamplifier configurations (including two hybrid preamplifiers). A graph showing the available system NEP performance versus avalanche gain with one of the best available avalanche detectors is presented.