Optical discs are often used by many private or public organizations to archive essential data. For a long time these media were supposed to be reliable. However, a loss of the stored data was highlighted, sometimes only after a few years of storage. This degradation was attributed to the discs ageing, without any identification of the materials involved in this ageing. This work aimed to determine the chemical and physical modifications resulting from the application of different stresses (photochemical, thermal and hydrolytic) on the materials used in optical discs : the CD-R polycarbonate substrates, the recording layers based on phthalocyanines and azo compounds, and the protective layers. The study of this last component allowed us to extend the researches to the case of the Blu-ray Disc. These physico-chemical modifications were then correlated to variations in digital and analog parameters of discs submitted to the same stresses. The ultimate objective of this work was to propose a general method that could help to understand the origin of the loss of information of optical discs submitted to stresses.
