Ion-exchange processes in active glasses: spectroscopic and structural characterization

The major force behind the recent advances in photonic components and devices has been the fast progress in optical fiber communication systems; as optical networks are spreading towards the final customers, the need of compact, low-cost and rugged integrated optical devices becomes more and more evident. Fabrication technologies, therefore, must be capable of high yield, with assured reproducibility within specified tolerances, and of intrinsic low operation cost. Among the various technological routes explored in the last decades, ion exchange is one that well fulfills the imposed requirements. Even the limitations due to the intrinsic passive nature of glassy materials have been overcome by using proper processing (e.g. phase separation) or introducing suitable dopants into the glass matrix; in this way, electro-optical and nonlinear-optical phenomena, as well as lasing and optical amplification were already demonstrated.