This review volume presents developments in the preparation, physical characterization and applications of insulating materials for optoelectronic applications. Insulators occupy a leading position as laser and optical amplifier hosts, electro-optic and acousto-optic modulators, frequency doublers and optical parametric oscillators, photorefractive devices and radiator detectors. These applications rely heavily on the development of advanced techniques for the preparation of both bulk and waveguide structures, the adequate knowledge of the microscopic behaviour defects, impurities and a...