Abstract: A method for forming waveguides in an optical material such as lithium niobate comprises the steps of providing an exchange agent including a proton-supplying medium and a catalyst, and exposing a selected portion of the optical material to the exchange agent for a predetermined time and at a predetermined temperature. Preferably, the catalyst is a metallic cation having a valence of at least +2, and the proton-supplying medium is a weak acid with a pKa of greater than about 4.5 or a lithium-buffered (“starved”) acidic solution. The catalyst accelerates the rate at which protons are exchanged with corresponding ions in the optical material lattice, thereby reducing the time required to produce a waveguide in the exposed portion of the optical material.

Abstract: Recycling process for CdTe/CdS thin film-solar cell modules in which the modules are mechanically disintegrated into module fragments, the module fragments are exposed to an oxygen-containing atmosphere at a temperature of at least 300° C. causing a pyrolysis of adhesive material contained in the module fragments in form of a hydrocarbon based plastics material and the gaseous decomposition products that are generated during the pyrolysis are discharged, and, afterwards, the module fragments freed from the adhesive means are exposed to a chlorine-containing gas atmosphere at a temperature of more than 400° C. causing an etching process wherein the CdCl2 and TeCl4 that are generated in the etching process are made to condense and precipitate by cooling.