The design, fabrication, and characterization of an 8×8 lossless optical switch, based on semiconductor optical amplifier (SOA) gates, is reported. It comprises three stages of 2×2 switches into an 8×8 Banyan switch, for a total of 48 SOAs. Three SOAs on each optical path provide gain to compensate for on-chip and fiber coupling loss, thereby making the optical switch lossless. All 64 optical paths demonstrate error-free 10 Gbps NRZ PRBS-31 transmission with at least 30 dB signal-to-noise ratio and less than 0.9 dB power penalty.