We propose a new code structure for Spectral-Amplitude Coding Optical Code Division Multiple Access (OCDMA) systems with zero cross-correlation and theoretically demonstrate the performance of this code by using a direct decoding technique. The proposed code can be adapted to any weight and user by using transformation and mapping techniques, respectively. The direct decoding technique is exploited since there is no overlapping occurrence in the code construction. The code performance shows that it outperforms the existing SAC OCDMA codes such as Hadamard, Modified Frequency Hopping (MFH) and Modified Double-Weight (MDW). The system can accommodate 120 simultaneous users for a bit error rate of 10-9.