Provided is a signal regenerator for correcting distortion of an optical signal transmitted via an optical fiber in an optical communication system, which includes semiconductor optical amplifiers having different lengths from each other, an asymmetric Mach-Zehnder interferometer that performs 2R (re-amplifying, re-shaping) regeneration, and a delay interferometer with optical waveguides having different lengths from each other, whereby the fabrication is easy and a high-speed signal regeneration is enable.