ABSTRACT
This chapter focuses on coherent optical CDMA. In a coherent OCDMA system, a given user’s code is generally applied via phase coding of the optical signal field, which is often derived from a highly coherent wideband source, such as a mode-locked laser. The receiver for a coherent OCDMA system relies on a coherent reconstruction of the signal field to recover the decoded user’s data. The chapter deals with a description of different coherent optical code-division multiple access (OCDMA) approaches based on spectral and temporal phase coding. It also focuses on OCDMA systems utilizing short-pulse mode-locked lasers as the source of coherent light and employing phase coding in either the temporal or spectral domain. The chapter presents a few of the more common formats applicable to the coherent OCDMA systems discussed. The operation of OCDMA system starts with a coherent ultra short pulse source shared between different transmitters, each having a distinct spectral phase mask.
