To overcome the technical bottleneck of low output optical power of swept laser source used in OCT (optical coherence tomography), a kind of Fourier domain mode-lock swept laser source was studied based on cascading SOA. A dual-ring swept laser source was built by using two semiconductor optical amplifiers(SOA) with the center wavelength of 1310nm. The output characteristics of the two SOA and the spectral output characteristics of dual ring swept laser were studied. The result shows that the optical power of the swept laser source is 28mW under the operating current of 280mA, the swept speed is up to 81.3kHz, the sweep range is beyond 90nm and the instantaneous linewidth is less than 0.03nm.
