5. Germanium substitutes

Research into substitutions has been limited to the most important jobs, but substitutes have not brought satisfactory results.

• Optical fibers

  The aim is to reduce the amount of germanium in germanium oxide glasses and replace it completely in fluoride glasses:

  • germanium oxide glasses, 30 to 76% GeO ₂ ; 15 to 20% alkali metals, 3 to 20% Al, Ga or In oxides ;

  • fluoride glasses: fluoroaluminates and fluorozirconates containing Zr, Ba, La, Al, Na. Although these glasses have very low transmission losses, they can only carry a fifth of the information obtained with conventional fibers.

• IR applications

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