The match between optical pulse source and en/decoders is an important issue in optical code dirision multiple access (OCDMA) system design. Half band application for equivalent phase shift superstructured fiber Bragg grating (EPS-SSFBG) en/decoder is proposed in this paper. The decode performance is fairly well when the source spectrum just cover half of the encode band which is decided by the SSFBG structure. The possibility of half band application is testified by both simulation and experiment.