TOAD-based all-optical gold code generator

Spread spectrum (SS) has proven to an efficient transmission scheme due to its antijamming and interference reduction capability. In multiuser environment, users are assigned distinguishable unique codes with low cross correlation (CC) values among each other. Gold sequences are an important class of sequences that allow construction of long sequences with three valued cross correlation function. Gold sequences are constructed from pairs of preferred m-sequences of the same length by modulo-2 addition. This paper presents a circuit realization of gold code in all-optical domain using semiconductor optical amplifier (SOA) based terahertz optical asymmetric demultiplexer (TOAD). Performance of the proposed optical realization is evaluated through numerical simulation, which confirms its feasibility in terms of the choice of the critical parameters.