Principles and Applications of Nonlinear Optical Elements in Fiber Optics Code Division Multiple Access Networks (FO-CDMA)

In this paper we introduce, for the first time, the use of nonlinear optical elements in fiber optics code division multiple access (FO-CDMA) networks using optical orthogonal codes, newly invented sets of orthogonal codes for positive systems, with desired auto- and cross correlation properties. Specifically, we consider a class of nonlinear optical elements in which their nonlinearities are achieved only as a result of their input light intensity. We use optical orthogonal codes to demonstrate the principles and advantages (e.g., reducing the interference signal´s intensity) of nonlinear optical elements in FO-CDMA environment. Then, system performance based on optical orthogonal codes and nonlinear optical elements in FO-CDMA is analyzed. For example, we show that, for an error rate of 10^¿10, FO-CDMA networks with nonlinear optical elements can accommodate 5 times as many more users w.r.t. FO-CDMA networks without the nonlinear optical elements.