The book "Digital Signal Processing In High-Speed Optical Fiber Communication: Principle and Application" offers a comprehensive introduction to the principles and applications of optical fiber communication based on digital signal processing (DSP). It covers both single-carrier and multi-carrier modulation and provides in-depth insights into the DSP techniques necessary for optimizing transmission performance in optical communication systems. In the context of single-carrier modulation, it addresses linear and nonlinear systems as well as the generation and processing of all-optical Nyquist modulation signals. For multi-carrier modulation, the generation and detection of OFDM signals are examined, including advanced modulation formats. Additionally, the use of artificial intelligence in optical fiber communication is discussed. This book is a valuable resource for students, researchers, and engineers involved in optical fiber communication.