Monitoring the Fabrication of Optical Ceramics by LIBS

Transparent optical ceramics (TOCs) are important optical materials with applications in street lightning, high-strength windows, electro- and magneto-optical isolators, high-power laser gain media and radiation detectors. Their fabrication relies, in most cases, on powder densification techniques carried out at high temperatures and often promoted by dopants, so-called 'sintering additives'. Achieving sufficient consistency in the fabrication process to guarantee high optical quality in the final product has proven to be a not-so-easy task however. In particular, a very precise control of stoichiometry, beyond the precision of current analytical techniques, is often required. This talk will present our most recent results on Laser-Induced Breakdown Spectroscopy (LIBS) for assessing stoichiometry shifts in Y3Al5O12 (YAG) and MgAl2O4 (spinel) ceramics with a precision well within the existence domain of these phases. We have also used this technique to monitor the concentration of sintering additives and unintentional impurities throughout the fabrication process of TOCs.