Chalcogenide glass material

Abstract

Provided is a small-diameter chalcogenide glass material having excellent weather resistance and mechanical strength and being suitable as an optical element for an infrared sensor. The chalcogenide glass material has an unpolished side surface, a pillar shape with a diameter of 15 mm or less, and a composition of, in terms of % by mole, 40 to 90% S+Se+Te and an inside of the glass material is free of stria with a length of 500 μm or more.

1 . A chalcogenide glass material having an unpolished side surface, a pillar shape with a diameter of 15 mm or less, and a composition of, in terms of % by mole, 40 to 90% S+Se+Te, an inside of the glass material being free of stria with a length of 500 μm or more. 
     
     
         2 . The chalcogenide glass material according to  claim 1 , wherein the side surface is a fire-polished surface. 
     
     
         3 . The chalcogenide glass material according to  claim 1 , containing, in terms of % by mole, over 0 to 50% Ge+Ga+Sb+As. 
     
     
         4 . The chalcogenide glass material according to  claim 1 , containing, in terms of % by mole, 0 to 40% Ge+Ga and 0 to 45% Sb+As. 
     
     
         5 . A method for producing a chalcogenide glass material, the method comprising drawing a glass base material containing, in terms of % by mole, 40 to 90% S+Se+Te by a redraw process. 
     
     
         6 . The method for producing a chalcogenide glass material according to  claim 5 , wherein a drawing temperature is equal to or lower than a glass transition point of the chalcogenide glass material plus 100° C. 
     
     
         7 . The method for producing a chalcogenide glass material according to  claim 5 , wherein the drawing is performed in a vacuum or in an inert atmosphere. 
     
     
         8 . An optical element using the chalcogenide glass material according to  claim 1 . 
     
     
         9 . An infrared sensor using the optical element according to  claim 8 .