Photosensitive and rare-earth doped ceramics for optical sensing: A review

This work reviews two inorganic materials classes used for optical sensors: photosensitive glasses and rare-earth doped materials. The underlying physical mechanisms contributing to the photosensitive response of germanosilicate glasses are discussed, along with a summary of optical sensor strategies which have been developed based upon photo-imprinted Bragg gratings. Particular attention is paid to the fabrication and characterization of photosensitive germanosilicate thin-films. Insights into the ability to control the photosensitivity of these materials through manipulation of material compositions and structures are also included. The discussion of rare-earth doped optical sensor materials emphasizes the important contribution of the host material to the observed optical behavior of the rare-earth ions. The use of rare-earth doped materials in applications ranging from temperature sensing to fiber-optic gyroscopes is also described.