After a brief examination of known insulating laser crystals and the stimulated emission channels of their generating activator ions, this article reviews recent advances in the development of novel lasing crystals and ceramics, as well as inorganic and organic nonlinear-laser crystals for χ (3) and cascaded χ (3) ↔ χ (2) frequency converters. Several new modern attractive technologies in the physics and techniques of crystalline lasers are also discussed.Section of the crystal structure of Na3Li (SeO4)