Spectroscopic Studies of Radiation Effects on Optical Materials

Optical materials, bulk glasses or optical fibers, offer many advantages for implementation in radiation environments such as the space, high-energy physics, nuclear industry, or medicine. The qualification of the materials then implies to develop "ad hoc" experimental spectroscopic techniques able to monitor the levels and kinetics of the radiation induced changes. Radiation–matter interaction, through ionization or displacement damage processes, gives rise to three main macroscopic effects: radiation-induced attenuation (RIA), radiation-induced emission, and radiation-induced compaction. The attenuation phenomenon is described by the Lambert–Beer law with the attenuation coefficient often expressed in cm -1 for bulk glasses and in dB m -1 or dB km -1 for optical fibers. The measured radiation-induced luminescence (RIL) spectrum results from the contribution from the various absorption bands associated with each of the radiation-induced point defects. The chapter is dedicated to two examples concerning the RIA on bulk and on optical fibers, and one about the RIL.