Silicon Germanium Core Fiber

Abstract

A process and apparatus for making silicon or silicon/germanium core fiber is described, which uses a plasma process with reducing agent to make a preform. The process also makes the recommendations in selecting the adequate cladding tube for better fiber properties. An improved fiber drawing apparatus is also disclosed in order to draw this new type of preform.

1 . An article of manufacture, comprising: a semiconductor core fiber product; and wherein the semiconductor core fiber product comprises silicon germanium material. 
     
     
         2 . The article of  claim 1  wherein the core comprises a mixture of silicon and germanium. 
     
     
         3 . The article of  claim 1  manufactured using a plasma chemical vapor deposition process with a reducing agent. 
     
     
         4 . The article of  claim 3  wherein the reducing agent is hydrogen. 
     
     
         5 . The article of  claim 3  wherein microwave plasma is utilized. 
     
     
         6 . The article of  claim 3  wherein plasma gases are argon and hydrogen. 
     
     
         7 . The article of  claim 6  in which the argon and the hydrogen have a ratio of between approximately 80/20 and 70/30. 
     
     
         8 . The article of  claim 3  in which a tubular member is used as deposition target. 
     
     
         9 . The article of  claim 8  in which the tubular member comprises glass tube. 
     
     
         10 . The article of  claim 8  in which pressure inside the tubular member is maintained at a range of 100 to 200 Torr lower than atmospheric pressure during deposition. 
     
     
         11 . The article of  claim 3  in which a furnace is at an operating temperature of between 500 and 1100 degrees C. 
     
     
         12 . The article of claim  31  in which the furnace is at an operating temperature of between 900 and 1000 degrees C. 
     
     
         13 . The article of  claim 2  manufactured using feed-in reaction chemicals comprising: Silane (SiH4) alone or with Hydrogen (H2), Silicon Tetrachloride (SiCl4) with Hydrogen (H2), or Trichlorosilane (SiHCl3) with Hydrogen (H2), along with either Germane (GeH4) or Germanium Tetrachloride (GeCl4). 
     
     
         14 . The article of  claim 1  in which the preform is drawn using both a furnace and a laser. 
     
     
         15 . The article of  claim 14  in which the furnace is maintained at a temperature which soften the cladding material of the preform. 
     
     
         16 . The article of  claim 14  in which the laser is used when a core material being drawn has a higher melting temperature than a cladding material and the laser energy is used to assist in melting the core material. 
     
     
         17 . The article of  claim 14  in which laser light from the laser is introduced through a set of mirrors or a window made of quartz or sapphire. 
     
     
         18 . The article of  claim 14  in which laser energy is absorbed by the core material and transmits through the cladding material. 
     
     
         19 . The article of  claim 14  in which pressure inside the preform is maintained at a range of 10 to 20 Torr lower than the atmospheric pressure while the preform is being drawn.