Process for optical communication and system for same

Abstract

The required penalty in the optical signal-to-noise ratio induced by nonlinear effects in an optical communication system is reduced by specific expedients. The communication system is operated and is adapted to be operated in a pseudo-linear regime. Further, an optical phase conjugator is employed with a suitable dispersion map. This combination yields a desirable improvement in the required penalty in the optical signal-to-noise ratio due to nonlinear effects.

We claim:  
     
         1 . A system for optical communication system comprising a system portion comprising at least two segments and an optical phase conjugator, said system portion configured to be a pseudo-linear regime system portion, wherein for said system portion the dispersion map ratio is in the range 0.5 to 2.0.  
     
     
         2 . The system of  claim 1  wherein said system further includes a receiver and said receiver comprises an optical signal to an electrical signal converter.  
     
     
         3 . The system of  claim 1  wherein said system further includes a receiver and said receiver comprises an optical signal regenerator.  
     
     
         4 . The system of  claim 3  wherein said optical signal regenerator reshapes said optical signal.  
     
     
         5 . The system of  claim 3  wherein said optical signal regenerator retmes said optical signal.  
     
     
         6 . The system of  claim 3  wherein said optical signal regenerator both retimes and reshapes said optical system.  
     
     
         7 . The system of  claim 1  wherein said system portion includes a fiber having a dispersion magnitude in the range 2 to 100 picoseconds/(nm·km).  
     
     
         8 . The system of  claim 1  wherein said dispersion map ratio is in the range 0.8 to 1.25.  
     
     
         9 . The system of  claim 8  wherein said dispersion map ratio is in the range 0.9 to 1.1.  
     
     
         10 . The system of  claim 1  wherein said optical phase conjugator is combined with a dispersion compensator.  
     
     
         11 . The system of  claim 1  wherein said system portion includes a multiplicity of optical phase conjugators.  
     
     
         12 . The system of  claim 1  wherein the power profile of the system portion is produced by discrete amplification.  
     
     
         13 . The system of  claim 1  wherein said system includes a multiplicity of optical amplifiers.  
     
     
         14 . The system of  claim 1  including a distributed Raman amplification source.  
     
     
         15 . A process for operating an optical communication system comprising propagating an optical signal through a system portion comprising at least two segments and an optical phase conjugator characterized in that 1) said system portion is operated in a pseudo-linear regime and 2) the system portion has a dispersion map ratio in the range 0.5 to 2.0.  
     
     
         16 . The process of  claim 15  wherein said system includes a receiver that comprises an optical signal to an electrical signal converter.  
     
     
         17 . The process of  claim 15  wherein said system includes a receiver that comprises an optical signal regenerator.  
     
     
         18 . The process of  claim 17  wherein said optical signal regenerator reshapes an optical signal.  
     
     
         19 . The process of  claim 17  wherein said optical signal regenerator retimes an optical signal.  
     
     
         20 . The process of  claim 17  wherein said optical signal regenerator retimes and reshapes an optical signal.  
     
     
         21 . The process of  claim 15  wherein said segment comprises a fiber having a dispersion in the range 2 to 100 psec/(nm·km)  
     
     
         22 . The process of  claim 15  wherein said dispersion map ratio is in the range 0.8 to 1.25.  
     
     
         23 . The process of  claim 15  wherein said dispersion map ratio in in the range 0.9 to 1.1.  
     
     
         24 . The process of  claim 15  wherein said optical phase conjugator includes a dispersion compensator.  
     
     
         25 . The process of  claim 15  wherein said system portion includes a multiplicity of optical phase conjugators.  
     
     
         26 . The process of  claim 15  wherein the power profile is produced by discrete amplification.