Index and density changes induced by proton radiation in lanthanum crown glass.

We studied the refractive index and density changes in cerium-doped lanthanum crown glass irradiated in air with 38.5 MeV protons. At a low proton fluence, the index change is linear with dose, and reaches 2.4x10[sup -5] at 2.7x10[sup 12] p/cm[sup 2] (0.65 Mrad dose). The rate of index change decreases with the proton fluence, but at high total dose (10[sup 14] p/cm[sup 2]) radiation-induced surface dilatation and birefringence start to appear. Our results show that the present concept of radiation-hard optical glass should be revised and that a high dose of proton radiation can produce index changes sufficient for the fabrication of integrated optical devices. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]