The information can’t be effectively intercepted by the conventional energy acquisition when the single user of optical code division multiple accesses (OCDMA) system uses two codes keying the modulation mode. The traditional intercepting way for multi-user OCDMA system is used when only one user emits the signal “1” and the other users emit the signal “0” in the system. The information interception has not real-time characteristic when the quantity of the OCDMA system users is large. Two different information intercepting schemes are designed to resolve the above problems in the two dimensional incoherent OCDMA system. First

it is assumed that the eavesdroppers know enough information such as the mode of en/decoding

the mode of constructing the address code

the transmission rate of the system

the value and quantity of wavebands etc. Then

the energy distribution of optical signals at different time and wavebands is achieved in the OCDMA system by using the advanced optoelectronic detection technique. Finally

the address codes existing in the OCDMA system can be deciphered effectively employing the energy distribution. The functions of the two intercepting schemes are simulated on the software platform of an incoherent OCDMA system that is designed using Optisystem software of Optiwave Ltd. and MATLAB in this paper. The OCDMA system has seven users and seven Reed-Solomon (R-S) codes received randomly. The interceptors can decipher the user signature codes effectively when the two codes keying is employed as the modulation way of the OCDMA system or the multi-users are in existent simultaneously according to the results of analysis. Therefore

the security problem still exists in the 2D incoherent OCDMA system.