Manufacturing process for chalcogenide glasses

Abstract

The present invention is generally directed to a method of making chalcogenide glasses including holding the melt in a vertical furnace to promote homogenization and mixing; slow cooling the melt at less than 10° C. per minute; and sequentially quenching the melt from the top down in a controlled manner. Additionally, the present invention provides for the materials produced by such method. The present invention is also directed to a process for removing oxygen and hydrogen impurities from chalcogenide glass components using dynamic distillation.

1 . A method of making chalcogenide glasses, comprising:
 heating the glass components to a melt temperature to form a melt;   holding the melt in a vertical furnace to promote homogenization and mixing;   slow cooling the melt by reducing the temperature less than 10° C. per minute; and   sequentially quenching the melt from the top down in a controlled manner.   
   
   
       2 . The method of  claim 1 , wherein the melt is slow cooled by reducing the temperature less than 5° C. per minute. 
   
   
       3 . The method of  claim 1 , wherein the sequential quench uses air flow. 
   
   
       4 . The method of  claim 1 , wherein the chalcogenide glass is a stable glass. 
   
   
       5 . The method  claim 4 , wherein the chalcogenide glass comprises arsenic sulfide or arsenic selenide. 
   
   
       6 . The method of  claim 4 , wherein the melt is cooled to within 50° C. above the glass transition temperature before quenching. 
   
   
       7 . The method of  claim 1 , wherein the chalcogenide glass is an unstable glass. 
   
   
       8 . The method of  claim 7 , wherein the melt is cooled to within 50° C. above the glass crystallization upon cooling temperature but below the liquidus temperature before quenching. 
   
   
       9 . The method of  claim 1 , wherein the chalcogenide glass is a rare earth doped chalcogenide glass. 
   
   
       10 . The method of  claim 9 , wherein the rare earth metal is praseodymium. 
   
   
       11 . The method of  claim 9 , wherein the chalcogenide glass comprises germanium, arsenic, gallium, and selenium. 
   
   
       12 . The method of  claim 9 , wherein the melt is cooled to within 50° C. above the glass crystallization upon cooling temperature but below the liquidus temperature before quenching. 
   
   
       13 . A high optical quality chalcogenide glass without refractive index perturbations prepared by a process comprising the steps of:
 heating the glass components to a melt temperature to form a melt;   holding the melt in a vertical furnace to promote homogenization and mixing;   slow cooling the melt by reducing the temperature less than 10° C. per minute; and   sequentially quenching the melt from the top down in a controlled manner.   
   
   
       14 . The chalcogenide glass of  claim 13 , wherein the melt is slow cooled by reducing the temperature less than 5° C. per minute. 
   
   
       15 . The chalcogenide glass of  claim 13 , wherein the chalcogenide glass is a stable glass. 
   
   
       16 . The chalcogenide glass  claim 15 , wherein the chalcogenide glass comprises arsenic sulfide or arsenic selenide. 
   
   
       17 . The chalcogenide glass of  claim 15 , wherein the melt is cooled to within 50° C. above the glass transition temperature before quenching. 
   
   
       18 . The chalcogenide glass of  claim 13 , wherein the chalcogenide glass is an unstable glass. 
   
   
       19 . The chalcogenide glass of  claim 18 , wherein the melt is cooled to within 50° C. above the glass crystallization upon cooling temperature but below the liquidus temperature before quenching. 
   
   
       20 . The chalcogenide glass of  claim 13 , wherein the chalcogenide glass is a rare earth doped chalcogenide glass. 
   
   
       21 . The chalcogenide glass of  claim 20 , wherein the rare earth metal is praseodymium. 
   
   
       22 . The chalcogenide glass of  claim 20  wherein the chalcogenide glass comprises germanium, arsenic, gallium, and selenium. 
   
   
       23 . The chalcogenide glass of  claim 20 , wherein the melt is cooled to within 50° C. above the glass crystallization upon cooling temperature but below the glass liquidus temperature before quenching. 
   
   
       24 . A method of removing oxygen impurities from chalcogenide glass components, comprising:
 providing a two-zone furnace having a first temperature zone and a second temperature zone;   providing a first chamber disposed in the first temperature zone and a second chamber in the second temperature zone, wherein the first chamber is fluidly connected to the second chamber such that vapors will transfer from the first chamber to the second chamber;   providing chalcogenide glass components in the first chamber in the presence of aluminum, zirconium, magnesium, or any combination thereof; and   heating the first chamber to a temperature greater than the second chamber, such that purified chalcogenide glass components distill into the second chamber leaving any oxygen impurities in the first chamber.   
   
   
       25 . A method of removing hydrogen impurities from chalcogenide glass components, comprising:
 providing a first chamber disposed in a furnace, wherein the first chamber is fluidly connected to a vacuum;   providing chalcogenide glass components in the first chamber in the presence of tellurium tetrachloride; and   heating the first chamber to a temperature to vaporize an HCl species from the chalcogenide glass components and withdrawing the HCl species from the first chamber via the vacuum.   
   
   
       26 . The method of  claim 25 , further comprising:
 providing a second chamber disposed outside of the furnace fluidly connected to the first chamber such that vapors will transfer from the first chamber to the second chamber;   providing rare-earth elements in the second chamber; and   distilling the chalcogenide glass components from the first chamber to the second chamber to form a rare-earth doped chalcogenide glass.