Patent ID: 6307984
Filing Date: 2001-10-23
Classification: H04B

Abstract:
An optical fiber communication system, comprising:a first optical fiber having a first end and a second end which correspond to an input end and an output end for a signal beam, respectively;a first phase conjugator operatively connected to said second end for converting the signal beam into a first phase conjugate beam and outputting the first phase conjugate beam;a second optical fiber having a third end and a fourth end which correspond to an input end and an output end for the first phase conjugate beam, respectively;a second phase conjugator operatively connected to said fourth end for converting the first phase conjugate beam into a second phase conjugate beam and outputting the second phase conjugate beam; anda third optical fiber having a fifth end and a sixth end which correspond to an input end and an output end for the second phase conjugate beam;said second optical fiber comprising a first portion located between said third end and a system midpoint and a second portion located between said system midpoint and said fourth end;the product of the average value of the chromatic dispersion and the length of said first optical fiber being substantially coincident with the product of the average value of the chromatic dispersion and the length of said first portion;the product of the average value of the chromatic dispersion and the length of said second portion being substantially coincident with the product of the average value of the chromatic dispersion and the length of said third optical fiber; andan optical band-pass filter provided in the proximity of said system midpoint of said second optical fiber and having a pass-band including the wavelength of the first phase conjugate beam, whereby noise produced by said optical amplifier is removed.