Optical technology is one of the key technologies that have been widely used for communication, computing and sensing. By utilizing different degrees of freedom for photon, optical signals can be detected and processed in different dimensions including amplitude, phase, polarization, time, frequency, and spatial mode. Multidimensional signal processing technologies have thus been broadly studied for improving the performance of communication, sensing and even computing systems. Recently, innovative optical signal processing methods and devices have been emerged to serve those needs driven by applications including but not limited to optical fiber transmission, supercontinuum generation, phase conjugation, free space optical communication, optical beamforming, photonic integration, fiber amplification, pose estimation and so on. This Special Issue aims to explore those emerging and enabling technologies of signal processing methods and devices for optical communication, optical computing, and optical sensing. The Special Issue consists of two review papers, one communication and seven articles within the areas of optical fiber transmission, specialty fiber design, 3D pose estimation, free space communication, digital signal processing, as well as photonic integration. Optical signal processing powered next generation communication, computing and sensing can be highly expected.

The key question of current optical communications research is: how to maximize both capacity and transmission distance in future optical transmission networks by using spectrally-efficient modulation formats with coherent detection, and how can digital signal processing aid in this quest? There is a clear trade-off between spectral efficiency and transmission distance, since the more spectrally-efficient modulation formats are also more susceptible to optical fiber nonlinearities. This chapter illustrates the application of nonlinear backpropagation to mitigate for both linear and nonlinear transmission impairments for a range of modulation formats, at varying symbol-rates and wavelength spacings, and also by varying the signal bandwidth which is backpropagated. The basics of coherent receiver structure and DSP algorithms for chromatic dispersion compensation, equalization and phase recovery of PDM-BPSK, PS-QPSK, PDM-QPSK, PDM-8PSK, PDM-8QAM, and PDM-16QAM are reviewed and the effectiveness of the nonlinearity compensating DSP based on digital backpropagation is explored. This chapter includes a comprehensive literature review of the key experimental demonstrations of nonlinearity-compensating DSP.

This book provides a comprehensive review of the state-of-the art of optical signal processing technologies and devices. It presents breakthrough solutions for enabling a pervasive use of optics in data communication and signal storage applications. It presents presents optical signal processing as solution to overcome the capacity crunch in communication networks. The book content ranges from the development of innovative materials and devices, such as graphene and slow light structures, to the use of nonlinear optics for secure quantum information processing and overcoming the classical Shannon limit on channel capacity and microwave signal processing. Although it holds the promise for a substantial speed improvement, today’s communication infrastructure optics remains largely confined to the signal transport layer, as it lags behind electronics as far as signal processing is concerned. This situation will change in the near future as the tremendous growth of data traffic requires energy efficient and fully transparent all-optical networks. The book is written by leaders in the field.

This book focuses on recent research and developments on optical communications. The chapters present different aspects of optical communication systems, comprising high capacity transmission over long distances, coherent and intensity modulated technologies, orthogonal frequency-division multiplexing, ultrafast switching techniques, and photonic integrated devices. Digital signal processing and error correction techniques are also addressed. The content is of interest to graduate students and researchers in optical communications.

The main objective of this book is to make respective graduate students understand the nonlinear effects inside SOI waveguide and possible applications of SOI waveguides in this emerging research area of optical fibre communication. This book focuses on achieving successful optical frequency shifting by Four Wave Mixing (FWM) in silicon-on-insulator (SOI) waveguide by exploiting a nonlinear phenomenon.