L-band dispersion compensating fiber and transmission system including same

Abstract

The present invention relates to a dispersion compensating optical fiber (“DC fiber”) having a segmented core of at least three segments and having a negative total dispersion and negative dispersion slope in the L-band. The index profile of the segmented core is selected to provide an optical fiber having properties suitable for a high performance communication system operating in the L-band wavelength band, i.e., between about 1570 nm to 1620 nm. The DC fiber according to the invention exhibits total dispersion at 1595 nm of between −95 and −225 ps/km/nm and dispersion slope more negative than −1.0 ps/km/nm 2 . The DC fiber may be optically connected to a non-zero dispersion shifted fiber in the system to compensate for dispersion and dispersion slope thereof.

What is claimed is:  
     
         1 . A dispersion compensating optical fiber, comprising: 
 a segmented core having at least three segments, the refractive index profile being selected to provide    total dispersion at 1595 nm between about −95 ps/nm-km and −225 ps/nm-km; and    a dispersion slope more negative than −1.0 ps/nm 2 -km at 1595 nm.    
     
     
         2 . The dispersion compensating optical fiber of  claim 1  wherein the total dispersion at 1595 nm is between about −110 ps/nm-km and −150 ps/nm-km.  
     
     
         3 . The dispersion compensating optical fiber of  claim 1  wherein the total dispersion is between about −80 ps/nm-km and −190 ps/nm-km over a wavelength range from about 1570 nm to 1620 nm.  
     
     
         4 . The dispersion compensating optical fiber of  claim 1  wherein at least one of the segments has an α-profile where a is between about 2.0 and 2.2.  
     
     
         5 . The dispersion compensating optical fiber  claim 1  wherein Δ 1 % is positive, Δ 2 % is negative, and Δ 3 % is positive.  
     
     
         6 . The dispersion compensating optical fiber of  claim 5  further comprising a central core segment having a positive Δ 1 % greater than 1.5%, a moat segment adjoining the central core segment and having a negative Δ 2 % more negative than −0.4%, and a ring segment adjoining the moat segment having a positive Δ 3 % greater than 0.7%.  
     
     
         7 . The dispersion compensating optical fiber of  claim 5  wherein a volume of the central core segment is in the range of about 9 units and 11 units, and a volume of the ring segment is in the range of about 40 units to 47 units.  
     
     
         8 . The dispersion compensating optical fiber of  claim 1  further comprising: 
 a central core segment having a Δ 1 % in the range of about 1.5% to 2.0% and a radius R 1  in the range of about 1.5 μm to 2.0 μm,  
 a moat segment having a Δ 2 % in the range of about −0.3% to −0.9% and a radius R 2  in the range of about 4.5 μm to 6.5 μm, and  
 a ring segment having a Δ 3 % in the range of about 0.6% to 1.1%, a mid point radius R 3  in the range of about 6.0 μm to 8.0 μm.  
 
     
     
         9 . The dispersion compensating optical fiber of  claim 1  further comprising: 
 a central core segment having a positive Δ 1 % greater than 1.7%,  
 a moat segment adjoining the central core segment having a negative Δ 2 % more negative than −0.5%, and  
 a ring segment adjoining the moat segment having a positive Δ 3 % greater than 0.8%.  
 
     
     
         10 . The dispersion compensating optical fiber of  claim 1  further comprising a volume of the ring segment greater than about 40 units.  
     
     
         11 . The dispersion compensating optical fiber of  claim 1  further comprising a ring segment having Δ 3 % of greater than 0.7%.  
     
     
         12 . The dispersion compensating optical fiber of  claim 11  further comprising a Δ 3 % of the ring segment between 0.7% and 1.0% and a midpoint radius R3 between 6.5 μm and 8.0 μm.  
     
     
         13 . The dispersion compensating optical fiber of  claim 1  further comprising: 
 a central core segment having a Δ 1 % in the range of about 1.7% to 1.9% and a radius R 1  in the range of between about 1.7 μm to 1.9 μm,  
 a moat segment having a Δ 2 % in the range of about −0.5% to −0.7% and an radius R 2  of between 5.0 μm and 6.0 μm, and a ring segment having a Δ 3 % in the range of about 0.75% to 0.9%, a midpoint radius R 3  in the range of about 6.5 μm to 8.0 μm, and a width in the range of about 0.7 μm to 1.2 μm.  
 
     
     
         14 . The dispersion compensating optical fiber of  claim 1  further including a kappa value defined as the dispersion at 1595 nm divided by the dispersion slope at 1595 nm of between 90 nm and 110 nm.  
     
     
         15 . The dispersion compensating optical fiber of  claim 1  further including a kappa value defined as the dispersion at 1595 nm divided by the dispersion slope at 1595 nm of between 90 nm and 105 nm.  
     
     
         16 . The dispersion compensating optical fiber of  claim 1  further including a kappa value defined as the dispersion at 1595 nm divided by the dispersion slope at 1595 nm of between 95 nm and 100 nm.  
     
     
         17 . The dispersion compensating optical fiber of  claim 1  further comprising a range of kappa values defined as the dispersion at a particular wavelength divided by the dispersion slope at the particular wavelength over the range of 1570 nm to 1620 nm of between 80 nm to 155 nm.  
     
     
         18 . The dispersion compensating optical fiber of  claim 17  further comprising a range of kappa values defined as the dispersion at a particular wavelength divided by the dispersion slope at the particular wavelength over the range of 1570 nm to 1620 nm of between 85 nm to 110 nm.  
     
     
         19 . The dispersion compensating optical fiber of  claim 1  further comprising a pin array of less than 7 dB at 1595 nm.  
     
     
         20 . The dispersion compensating optical fiber of  claim 1  further comprising a cutoff wavelength for a next higher order mode above LP 01 , the cutoff wavelength being less than 2025 nm.  
     
     
         21 . The dispersion compensating optical fiber of  claim 1  further comprising an effective area at 1595 nm of greater than 15 μm 2 .  
     
     
         22 . The dispersion compensating optical fiber of  claim 21  further comprising an effective area at 1595 nm of greater than 17 μm 2 .  
     
     
         23 . The dispersion compensating optical fiber of  claim 1  further comprising an dispersion slope over the wavelength range of between about 1570 nm and 1620 nm of between −0.7 ps/nm 2 -km and −2.5 ps/nm 2 -km.  
     
     
         24 . The dispersion compensating optical fiber of  claim 23  further comprising an dispersion slope over the wavelength range of between about 1570 nm and 1620 nm of between −1.0 ps/nm 2 -km and −1.8 ps/nm 2 -km.  
     
     
         25 . The dispersion compensating optical fiber of  claim 1  further comprising an dispersion slope at 1595 nm of between −1.0 ps/nm 2 -km and −2.5 ps/nm 2 -km.  
     
     
         26 . The dispersion compensating optical fiber of  claim 1  further comprising an dispersion slope at 1595 nm of between −1.2 ps/nm 2 -km and −1.5 ps/nm 2 -km.  
     
     
         27 . The dispersion compensating optical fiber of  claim 1  further comprising an dispersion slope at 1595 nm more negative than −1.2 ps/nm 2 -km.  
     
     
         28 . The dispersion compensating optical fiber of  claim 1  further comprising dispersion slope that is more negative than −0.7 ps/nm 2 -km over the entire L-band from 1570 nm to 1620 nm.  
     
     
         29 . The dispersion compensating optical fiber of  claim 28  further comprising a dispersion slope that is more negative than −1.2 ps/nm 2 -km over the entire L-band from 1570 nm to 1620 nm.  
     
     
         30 . The dispersion compensating optical fiber of  claim 1  further comprising: 
 a central core segment having an outer radius R 1  in the range of between about 1.5 μm and 2.0 μm,  
 a moat segment having an outer radius R 2  in the range of between about 4.5 μm and 6.5 μm, and  
 a ring segment having a midpoint radius R 3  in the range of between about 6.0 μm to 8.0 μm.  
 
     
     
         31 . The dispersion compensating optical fiber of  claim 30  further comprising a an outer radius R 4  of the ring segment in the range of between about 10 μm and 12 μm.  
     
     
         32 . An optical transmission system having a dispersion compensating optical fiber, wherein the dispersion compensating fiber comprises: 
 a segmented core having at least three segments, the refractive index profile being selected to provide    total dispersion at 1595 nm between about −95 ps/nm-km and −225 ps/nm-km; and    a dispersion slope more negative than −1.0 ps/nm 2 -km at 1595 nm.    
     
     
         33 . The optical transmission system of  claim 32  further comprising a non-zero dispersion shifted fiber coupled to the dispersion compensating fiber, the non-zero dispersion shifted fiber having a dispersion slope of between about 0.065 and 0.08 ps/nm 2 -km at 1595 nm.  
     
     
         34 . The optical transmission system of  claim 33  wherein the non-zero dispersion shifted fiber has a dispersion of between about 6.5 and 8.5 ps/nm-km at 1595 nm.