All-Optical Signal Processing

TLDR

Optical signal processing combines nonlinear devices, analog and digital signals, and advanced modulation formats to enable high‑speed functions at fiber‑optic line rates, using amplitude, phase, wavelength, polarization, and spatial encoding for high‑capacity transmission and exploiting nonlinearities and dispersion for wavelength conversion, multicasting, multiplexing, demultiplexing, and tunable delays. The authors revisit advances in key enabling technologies for optical signal processing of digitally encoded signals across multiple dimensions. They review recent high‑speed optical signal‑processing applications such as equalization, regeneration, flexible signal generation, and optical logic and correlation.

Abstract

Optical signal processing brings together various fields of optics and signal processing - namely, nonlinear devices and processes, analog and digital signals, and advanced data modulation formats - to achieve high-speed signal processing functions that can potentially operate at the line rate of fiber optic communications. Information can be encoded in amplitude, phase, wavelength, polarization and spatial features of an optical wave to achieve high-capacity transmission. We revisit advances in the key enabling technologies that led to recent research in optical signal processing for digital signals that are encoded in one or more of these dimensions. Various optical nonlinearities and chromatic dispersion have been shown to enable key sub-system applications such as wavelength conversion, multicasting, multiplexing, demultiplexing, and tunable optical delays. We review recent advances in high-speed optical signal processing applications in the areas of equalization, regeneration, flexible signal generation, and optical control information (optical logic and correlation).