Novel scheme for all-optical AND gate based on cross-gain modulation in cascaded two stage semiconductor optical amplifiers (SOAs) is presented. Single-port-coupled SOA is exploited in the first stage to improve the output extinction ratio, input power of the second stage is properly controlled, and 2.5 Gbit/s all-optical logic AND operation is demonstrated experimentally. Operation principle is illustrated and experimental results are analyzed in detail. According to the experimental results, the extinction ratio of the output signal from the first stage and the optical power into the second stage are very important to the final results of this logic AND gate. So if these factors are controlled properly, the output performance of the logic AND gate can be effectively improved.