Layered glass structures

Abstract

Layered glass structures and fabrication methods are described. The methods include depositing soot on a dense glass substrate to form a composite structure and sintering the composite structure to form a layered glass structure. The dense glass substrate may be derived from an optical fiber preform that has been modified to include a planar surface. The composite structure may include one or more soot layers. The layered glass structure may be formed by combining multiple composite structures to form a stack, followed by sintering and fusing the stack. The layered glass structure may further be heated to softening and drawn to control linear dimensions. The layered glass structure or drawn layered glass structure may be configured as a planar waveguide.

What is claimed is: 
     
         1 . A method of making a layered glass structure comprising:
 stacking a first dense glass layer on a composite structure, said composite structure including a first soot layer on a second dense glass layer, said first soot layer having a thickness of at least 100 μm.   
     
     
         2 . The method of  claim 1 , wherein said second dense glass layer comprises silica glass. 
     
     
         3 . The method of  claim 2 , wherein said first dense glass layer comprises silica glass. 
     
     
         4 . The method of  claim 1 , wherein said first soot layer has a density in the range from 0.30 g/cm 3  to 1.50 g/cm 3 . 
     
     
         5 . The method of  claim 1 , wherein said first soot layer comprises silica glass. 
     
     
         6 . The method of  claim 5 , wherein said silica glass comprises a luminescent dopant. 
     
     
         7 . The method of  claim 5 , wherein said silica glass comprises Al 2 O 3 , GeO 2 , TiO 2 , or Ga 2 O 3 . 
     
     
         8 . The method of  claim 7 , wherein said silica glass further comprises a rare earth dopant. 
     
     
         9 . The method of  claim 1 , wherein said thickness of said first soot layer is at least 1 mm. 
     
     
         10 . The method of  claim 1 , wherein said first soot layer is formed on a planar surface of said first dense glass substrate. 
     
     
         11 . The method of  claim 10 , wherein said planar surface has a length of at least 0.1 m. 
     
     
         12 . The method of  claim 11 , wherein a ratio of said length of said planar surface to a width of said planar surface is at least 2.0. 
     
     
         13 . The method of  claim 11 , wherein a ratio of said length of said planar surface to a width of said planar surface is at least 10. 
     
     
         14 . The method of  claim 10 , wherein said planar surface has a length of at least 0.5 m. 
     
     
         15 . The method of  claim 1 , wherein said stacking comprises directly contacting said first dense glass layer and said first soot layer. 
     
     
         16 . The method of  claim 1 , further comprising consolidating said stacked structure. 
     
     
         17 . The method of  claim 16 , wherein said consolidating comprises consolidating said first soot layer, said consolidated first soot layer having a thickness of at least 100 μm. 
     
     
         18 . The method of  claim 1 , further comprising forming said composite structure. 
     
     
         19 . The method of  claim 1 , wherein said composite structure further comprises a second soot layer on said first soot layer, said second soot layer differing in composition from said first soot layer. 
     
     
         20 . The method of  claim 1 , further comprising drying said first soot layer.