Glasses containing rare earth fluorides

Abstract From the Canadian patent

This process provides a new way to embed rare earth fluorides into silica (or germania-doped silica) glasses by solution chemistry. Embedding rare earth fluorides into a silica (or germania-doped silica) glasses comprises the following steps. The first step forms a porous silica core preform by OVD process. The second step submerges the preform into an aqueous solution of rare earth ions. The third step removes the preform from the solution and washes the outside surfaces of the preform. The fourth step submerges the preform into an aqueous solution of a fluorinating agent such as ammonium , bifluoride, HF or KF. Rare earth trifluorides precipitate out from the solution and deposit …