Heavy-metal fluoride glass of zirconium, barium, lanthanum, aluminium, and sodium fluorides, transparent into the mid-infrared.
Core Principles & Analysis
ZBLAN was discovered accidentally by the Poulain brothers at the University of Rennes in 1974 while working with zirconium fluoride crystals.
It transmits light from about 0.3 to 7 µm, far beyond the infrared cutoff of silica, and doped ZBLAN fibers make mid-infrared fiber lasers.
Because crystallization during fiber drawing is aggravated by convection, ZBLAN optical fiber has been experimentally drawn in microgravity aboard the ISS.