Simple robust receiver structure for gigabit ethernet O-CDMA using matrix codes

We have developed an optical code division multiple access (O-CDMA) technology demonstrator (TD) based on two-dimensional (2-D) codes. The 2-D codes are derived from folded optimum Golomb rulers, implemented as wavelength/time lambda/T codes. The objective of the research is to develop the science and technology for high-performance, low-cost, and robust O-CDMA applications. A key ingredient of the TD is a simple receiver structure that is based on hard-limiting after optical-to-electrical (O/E) conversion and time windowing with a conventional electronic D flip-flop. With the TD, we demonstrate six asynchronous users at less than 10(-11) bit error rate (BER) and up to eight users at 10(-8) BER, limited by saturation in the optical preamplifier.