Optical CDMA by amplitude spectral encoding of spectrally-sliced light-emitting-diodes

The aim of this work is to prove feasibility of an optical code division multiple access (CDMA) system based on incoherent encoding of spectrally-sliced broadband light sources. Light-emitting-diodes (LEDs) are employed in a multi-mode fiber-optics system and m-sequences are used for the optical encoding. A double-pass configuration with a Littrow grating is used in the optical encoder and decoder. A differential receiver with a simplified optical arrangement is employed. The optical set-up allows one to increase the compactness and power throughput. The system processing gain has been studied in a two-user experiment. Bit error rate (BER) measurements are presented and system issues are discussed. It is verified that with line rates of up to 500 Mbps, an aggregate throughput in the order of 50 Gbps can be achieved at the present state of the art