Air Force Measures Refractive Index of BGG

Barium gallogermanate glasses are extraordinarily strong yet still exhibit a transmission region from 0.4 to 5.0 µm, making them seemingly ideal for a vast array of large-optic applications. A team from the US Air Force Research Laboratory at Wright-Patterson Air Force Base in Ohio has measured the refractive index of the glass using a modified spectrometer from Moeller-Wedel Optical GmbH of Wedel, Germany. The measurements, made with the minimum deviation method, are published in the March 1 issue of Applied Optics. The team expects the information to be especially helpful in the development of antireflection coatings for windows and domes made from the material.