Fiber optic article including fluorine

Abstract

A fiber optic article, such as an optical fiber or an optical preform, can include a core comprising a concentration of erbium, a concentration of fluorine and a concentration of ytterbium for sensitizing the erbium by absorbing pump light and transferring energy to the erbium. The erbium can provide light having a second wavelength different than the wavelength of the pump light. The article can also include a concentration of phosphorus. The fiber optic article can include a cladding disposed about the core, where the cladding has an index of refraction that is less than the index of refraction of the core, and a second cladding disposed about the first cladding, where the second cladding includes an index of refraction than is less than the index of refraction of the cladding. The fiber optic article can be elongate along a longitudinal axis and can include a longitudinally extending region for providing birefringence.

1 . A glass fiber optic article, comprising: 
 a core comprising a concentration of erbium, a concentration of fluorine and a concentration of ytterbium for sensitizing said erbium by absorbing pump light and transferring energy to said erbium, said erbium providing light having a second wavelength different than the wavelength of the pump light, and    a cladding disposed about said core, said cladding having an index of refraction that is less than an index of refraction of said core.    
     
     
         2 . The fiber optic article of  claim 1  wherein said core comprises phosphorus.  
     
     
         3 . The fiber optic article of  claim 1  wherein said concentration of erbium includes a concentration of erbium ions and wherein said concentration of ytterbium includes a concentration of ytterbium ions that is at least 2 times greater than said concentration of erbium ions.  
     
     
         4 . The fiber optic article of  claim 3  wherein said concentration of ytterbium ions is at least 6 times greater than said concentration of erbium ions.  
     
     
         5 . The fiber optic article optical fiber of  claim 3  wherein said concentration of ytterbium ions is at least 10 times greater than said concentration of erbium ions.  
     
     
         6 . The fiber optic article of  claim 3  wherein said concentration of ytterbium ions is at least 20 times greater than said concentration of erbium ions.  
     
     
         7 . The fiber optic article of  claim 1  comprising a second cladding disposed about said cladding, said second cladding having an index of refraction that is less than the index of refraction of said cladding.  
     
     
         8 . The fiber optic article of  claim 1  wherein said core comprises a numerical aperture of no greater than 0.09.  
     
     
         9 . The optical fiber of  claim 1  wherein said core comprises a numerical aperture of no greater than 0.06.  
     
     
         10 . The fiber optic article of  claim 1  wherein article is an optical fiber and said core has a V-number of at least 3 at said second wavelength.  
     
     
         11 . The fiber optic article of  claim 1  wherein said article is an optical fiber and said core has a V-number of at least 4 at said second wavelength.  
     
     
         12 . The fiber optic article of  claim 1  wherein said article is an optical fiber and said core comprises a V-number of at least 6 at said second wavelength.  
     
     
         13 . The fiber optic article of  claim 1  wherein said core comprises at least 60% by weight of silica.  
     
     
         14 . The fiber optic article of  claim 1  wherein said core comprises at least 70% by weight of silica.  
     
     
         15 . The fiber optic article of  claim 1  wherein said concentration of fluorine is at least 1% by weight.  
     
     
         16 . The fiber optic article of  claim 1  wherein said concentration of fluorine is at least 3% by weight.  
     
     
         17 . The fiber optic article of  claim 1  wherein said concentration of fluorine is from 0.1% to 3.5% by weight.  
     
     
         18 . The fiber optic article of  claim 1  wherein said article is an optical fiber and wherein said core comprises a diameter of at least 12 microns.  
     
     
         19 . The fiber optic article of  claim 1  wherein said article is an optical fiber and wherein said core comprises a diameter of at least 15 microns.