Ion-exchange in Glasses and Crystals: from Theory to Applications

Since its first observation in 1850 ion-exchange (IEx) has become a fundamental process in many applications involving water treatment catalysis chromatography and the food and pharmaceutical industries. Starting from the early 1900s another relevant application of IEx has been in the glass industry with the surface tempering of glass produced by a K+-Na+ ion exchange. Nowadays photonics has greatly exploited IEx technology: graded-index microlenses graded-index fibers and integrated optical waveguides and devices are examples of achievements made possible by the IEx process. Moreover ion-exchange is possible in ferroelectric crystals too and has been fundamental for the development of many linear and nonlinear integrated optical devices in lithium niobate and tantalate.