In this book Optical Code Division Multiple Access (OCDMA) system plays a vital role in long haul and high speed communication networks like LAN and MAN. These systems have advantage of high speed, large capacity and huge bandwidth. The TDMA, WDMA and CDMA are available major multiple access techniques. Both TDMA and WDMA system require time or frequency management system however the CDMA system does not require any centralized control and thereby reduce the complexity of the system. Optical CDMA combines the large bandwidth of the fiber medium with the flexibility of the CDMA technique to achieve the high-speed connectivity. The establishment of OCDMA needs to overcome the code orthogonality problem and also in 1-D optical orthogonal codes, the ratio of code length to the code weight grows rapidly as the number of users increases. Incoherent OCDMA scheme based on wavelength/time (W/T) codes has been proposed in this project. Using a power normalizer, a W/T OCDMA system is built to support 32 simultaneous users for a 180 km long link with bit error rate (BER) 10-26 Skryť popis