US Patent 7373792 Method for producing optical components

For producing large volume optical components of high optical quality from synthetic quartz glass blanks, the latter are heated in a component mold in a furnace with a protective gas atmosphere to a temperature 50° to 170° K above the softening point, this temperature being held for 20 to 90 minutes and, during this holding time, the quartz glass blank being pressed into the component mold. By these means, a gentle treatment of the quartz glass, a good yield, a decrease in the energy input and a complete filling up of the component mold are achieved.