An all-optical AND gate using photonic-crystal quantum dot semiconductor optical amplifiers is designed and its performance is evaluated. The input–output characteristics of the gate are simulated using a rate equation model and it is found that the gate can achieve a maximum of ∼9 dB extinction ratio at 160 Gb/s. The proposed gate is compared with quantum dot semiconductor optical amplifiers AND gate to evaluate its effectiveness with regard to signal quality, device size, and power consumption.