Recently, there has been increasing interest in field of Optical CDMA due to its potential for offering unmatched features at ultra high data rates in field of local and metro area networks. OCDMA exhibits as an attractive alternative for broadband fiber optic multiple access networks among other optical multiplexing technologies such as OTDMA (Optical Time Division Multiple Access) and WDMA (Wavelength Division Multiple Access) Optical CDMA is a technique where different codes are assigned to different users. Each user data bit is spreaded according to the code allotted to it.Aim of the book is to discuss very simple method of Optical CDMA encoding technique known as the Temporal Phase Encoding and the performance of the system with this encoding technique is evaluated on the basis of number of users, length of the spreading code for 4-phase and 8-phases. Simulation results for the system are presented for upto seven users. Bit error rate curves are plotted with data rate of 1Gbps.