Presents a method for development of a new novel in optical code for Optical Code Division Multiple Access (OCDMA) system using Spectral Amplitude Coding (SAC). The proposed code is called Sequential Algorithm (SeQ) code. From theory, the proposed method is to construct optical codes with a combination of tridiagonal matrix and identify matrix code. This SeQ code is constructed with simple code construction for any number of users and weight, various cross correlation and having minimum code length. SeQ code has been designed with cross correlation is equaling to zero and one due to the effects of Multiple Access Interference (MAI) thus to prevent from overlapping of spectra from each users. These codes are easy to construct, simple and have better noise performance compared with existing optical codes such as Flexible Cross Correlation (FCC), Dynamic Cyclic Shift (DCS), Modified Frequency Hopping (MFH) and Modified Double Weight (MDW) code. The requirement in OCDMA systems to enhanced performance of BER is the reason why these codes has been designed. The performances of SeQ code has been done via theoretical analysis and simulated performances analysis via utilizing commercial simulation software, Optisystem by OptiwaveTM. The performance of the systems was characterized by referring the Bit Error Rate (BER), signal-to-noise ratio (SNR), bit rate and effective received power. This research finds strong performance of SeQ code when compared between theoretical and analysis performance and the result was proportional each other. Therefore, SeQ code has enhanced the OCDMA system better than existing codes.
