In the last decade, China has experienced one of the fastest economic growth in the world. Leading this enormous growth is the development of telecommunications that has a growth rate far exceeding that of its GNP. With such fast growth, China will have the largest telecommunication network with 420 million lines by 2010. The backbone of the national telecom network in China is primarily optical fiber cables today.This book contains a selection of reports reviewing the progress of the research and development in optoelectronics and optical fiber communications in China. The first four papers focus on the current development in optical fiber communications with particular interest in studies of soliton transmission and optical WDM transmission experiments. The next four papers describe the research results on quantum well lasers, bi-stable lasers, electro-absorption modulators and SEED, and photonic integrated devices. Fiber ring lasers using EDFA and the ASE noise in the PIN receiver due to EDFA are discussed in the next two papers, respectively. The last two papers describe the research activities and results of the development of the GaAs ICs for high speed lighwave systems, and their characterization using optical sampling techniques. The contents included in this book may be regarded as the epitome of the current status of research in this field in mainland China.