ABSTRACT
This chapter discusses various coding techniques and enabling hardware technologies of the seven major categories of optical coding schemes. There are two main categories of optical coding schemes—synchronous and asynchronous—depending on whether synchronization is needed among optical codewords. The chapter explains the special technique of supporting multirate, multimedia services in coding-based optical systems and networks by means of multiple-length codes. It talks about multicode keying and shifted-code keying for increasing bit rate. To achieve high bit rate or spectral efficiency in coding-based optical systems and networks, the concept of multiple-bit-per-symbol transmission has been introduced by means of pulse-position modulation, multicode keying, and shifted-code keying. The chapter explores designs of coding devices, based on arrayed waveguide gratings and fiber Bragg gratings. It also discusses various potential applications of optical coding, in addition to Optical Code-Division Multiple Access. As hardware technologies mature, optical coding has been gathering attention and proposed for various applications.
