Preface This is an annual report on the research activities in the field of optical communications and high-speed electron devices for 1994 at Faculty of Engineering, Tokyo Institute of Technology. 　 These activities are initiated by Professor Y.Suematsu (emeritus, the former president), and Professor S.Arai [Group A], mainly in the field of Integrated Dynamic-Single-Mode Lasers and Laser Amplifiers, Low- dimensional Quantum-well Lasers, and also in the fabrication of ultra-fine structures; 　 This report consists of a brief introduction of the research activities and a collection of the research papers published in 1994.