We have studied experimentally, by using a differential interferometric technique, the effect of proton radiation on the refractive index of commercial (Schott) silicate crown glasses, BK7 and LaK9, and their radiation-resistant counterparts. The strongest effect was observed for the radiation-hard lanthanum crown LaK9G15: At a 0.65-Mrad dose the index change was approximately 3 × 10<sup>−5</sup>. Radiation-hard glasses are used in optical systems operating in radiation environments because they prevent spectral transmission degradation in the visible. However, such glasses are not protected against radiation-induced refractive-index perturbations, and a diffraction-limited optical system based on such glasses may fail owing to radiation-induced aberrations.
© 2002 Optical Society of America
Andrei I. Gusarov, Dominic Doyle, Alex Hermanne, Francis Berghmans, Michel Fruit, Gerd Ulbrich, and Michel Blondel, "Refractive-Index Changes Caused by Proton Radiation in Silicate Optical Glasses," Appl. Opt. 41, 678-684 (2002)