Patent ID: 7415177

Claim:
A dispersion compensation method for an optical signal comprising the steps of: selecting a second dispersion compensatine fiber from between an optical reflecting unit for reflecting the optical signal and the second dispersion compensating fiber; dispersion compensating said optical signal by passing it through a first dispersion compensating fiber; outputting the optical signal passed through said first dispersion compensating fiber to the second dispersion compensating fiber; dispersion compensating said optical signal by passing it through the second dispersion compensating fiber; reflecting said optical signal passed through said second dispersion compensating fiber to pass back the optical signal through said second dispersion compensating fiber in the opposite direction to dispersion compensate the optical signal; and dispersion compensating said optical signal returned from said second dispersion compensating fiber by passing again said first dispersion compensating fiber in the opposite direction; wherein, in case that said optical signals passed through said first dispersion compensating fiber is outputted to the optical reflecting unit, said optical signal is dispersion compensated by said first dispersion compensating fiber twice and two ways without using said second dispersion compensating fiber.