In this paper, we present a single photodiode detection (SPD) technique for spectral-amplitude coding optical code-division multiple-access (SAC-OCDMA) systems. The proposed technique eliminates both phase-induced intensity noise (PIIN) and multiple-access interference (MAI) in the optical domain. Analytical results show that for 35 simultaneous users transmitting at data rate of 622 Mbps, the bit-error rate (BER) = 1.4 x 10(-28) for SPD technique is much better compared to 9.3 x 10(-6) and 9.6 x 10(-3) for the modified-AND(n) as well as the AND(a) detection techniques, respectively. Moreover, we verified the improved performance afforded by the proposed technique using data transmission simulations. [DOI: http://dx.doi.org/10.2971/jeos.2013.13022]