Optical transmission systems including optical amplifiers and methods of use therein

Abstract

Optical transmission systems of the present invention include a plurality of optical amplifiers configured to provide optical amplification of one or more information carrying optical signal wavelengths. At least two of the optical amplifier are operated to provide net losses or net gains along corresponding spans, while the cumulative gain provided by the plurality of optical amplifiers substantially compensates for the cumulative loss of the spans.

What is claimed is:  
     
         1 . A method of amplifying optical signals comprising: 
 providing a plurality of optical amplifiers, each configured to provide optical amplification to optical signals to compensate substantially for a corresponding span loss along a span;    operating at least two of the optical amplifiers such that the optical amplification does not compensate for the span loss and produce one of net gain or net loss along the spans; and,    controlling the plurality of optical amplifiers such that the cumulative optical amplification provided by the plurality of optical amplifiers substantially compensate for the cumulative loss of the corresponding span losses.    
     
     
         2 . The method of  claim 1 , wherein: 
 said operating includes operating an equal number of optical amplifiers to produce a net gain as to produce a net loss.    
     
     
         3 . The method of  claim 1 , wherein: 
 said operating includes operating a number of optical amplifiers to produce a net gain that is not equal to a number of optical amplifiers operated to produce a net loss.    
     
     
         4 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers to produce a net gain preceding a net loss.    
     
     
         5 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that a net gain is offset by net loss in subsequent amplifiers.    
     
     
         6 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that a net gain is offset by net loss from at least one of the other of said amplifiers.    
     
     
         7 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that net gain offsetting net loss in at least one amplifier is distributed over at least two of the other amplifiers.    
     
     
         8 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that a net loss is offset by net loss from at least one of the other of said amplifiers.    
     
     
         9 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that a cumulative net gain does not exceed a maximum net gain.    
     
     
         10 . The method of  claim 1 , wherein: 
 said operating includes operating the plurality of optical amplifiers such that a cumulative net loss does not exceed a maximum net loss.    
     
     
         11 . The method of  claim 1 , wherein: 
 said providing includes providing the plurality of optical amplifiers configured to provide a cumulative optical amplification that substantially compensates for the cumulative span loss, when at least one of the plurality of optical amplifiers fails.    
     
     
         12 . The method of  claim 1 , wherein: 
 said operating includes operating all, but at least two, of the optical amplifiers such that the optical amplification substantially compensates for the span loss.    
     
     
         13 . An optical system comprising: 
 at least one transmitter;    at least one receiver; and,    a plurality of optical amplifiers disposed along a an optical path between said at least one transmitter and said at least one receiver to provide cumulative gain that substantial compensate for a cumulative loss of said optical path, wherein at least two of said optical amplifiers provide optical amplification that does not compensate for loss along a span of said optical path and produce at least one of net gain and net loss along the corresponding spans.    
     
     
         14 . The system of  claim 13 , wherein said at least two optical amplifiers produce one of net gain and net loss along the corresponding spans.  
     
     
         15 . The system of  claim 13 , wherein at least one of said optical amplifiers produce both net gain and net loss along the corresponding span.  
     
     
         16 . The system of  claim 13 , wherein said transmitters and receivers communicate with said optical path via at least one integrated switching device.  
     
     
         17 . A computer readable medium comprising: 
 a set of instructions that when executed perform at least the following,    adjust amplifier gains provided by a plurality of optical amplifiers to compensate for a cumulative loss in a corresponding plurality of individual spans; and,    provides for at least one of net gain and net loss in individual spans amplified by at least two of said optical amplifiers.    
     
     
         18 . The medium of  claim 17 , wherein said set of instructions is executed by a network management system.  
     
     
         19 . The medium of  claim 17 , wherein said set of instructions is executed by at least one processor in a network management system.  
     
     
         20 . The medium of  claim 17 , wherein said at least one processor includes at least a portion of the computer readable medium as memory.  
     
     
         21 . The medium of  claim 17 , wherein said set of instructions is executed by a plurality of distributed processors in a network management system.  
     
     
         22 . The medium of  claim 17 , wherein said set of instructions is executed by a network management system managing an optical system including said optical amplifiers.  
     
     
         23 . A method of selecting optical amplifiers comprising: 
 selecting a plurality of optical amplifiers for a corresponding plurality of span losses to provide a cumulative gain that compensates for the plurality of span losses, and wherein at least two of said optical amplifiers are selected to provide at least one of net gain and net loss relative to corresponding span losses.    
     
     
         24 . The method of  claim 23 , wherein said selecting includes selecting the at least two optical amplifiers to vary system performance.  
     
     
         25 . The method of  claim 23 , wherein said selecting includes selecting the at least two optical amplifiers to reduce cumulative noise figure of the plurality of optical amplifiers.  
     
     
         26 . The method of  claim 23 , wherein said selecting includes selecting the at least two optical amplifiers to increase cumulative gain margin for the plurality of optical amplifiers.  
     
     
         27 . The method of  claim 23 , wherein said selecting includes selecting the at least two optical amplifiers to vary spectral gain variations produced by the plurality of optical amplifiers.