Experimental demonstration of spectrally encoded optical CDMA systems using Mach-Zehnder encoder chains

Summary form only given. Recently, there has been tremendous interest in applying spread spectrum and code division multiple access (CDMA) techniques in optical fiber communication systems. Contrary to radio CDMA systems, which employs electric-field encoding and correlation to achieve orthogonality, most of the optical communication systems use intensity modulation and direct detection. To achieve true orthogonality in optical CDMA systems, the balanced detection scheme and spectral intensity coding need to be used. We shows the block diagram of the bipolar spectrally encoded CDMA system. The transmitter consists of a pair of broadband optical sources connected in a balanced fashion. The input data differentially modulate the intensity of the two balanced sources.