Potassium tantalate niobate crystals: Efficient quadratic electro-optic materials and their laser modulation technology

Electro-optic (EO) crystals are important material for all-solid-state laser technology, which can be used to fabricate various laser modulators, such as EO switches, laser deflectors, and optical waveguide. The improvements in new high-efficiency EO crystal materials have held great significance to the development of laser technology. Potassium tantalate niobate (KTN) is a popular multifunctional crystal because of its remarkable and excellent quadratic EO effect. KTN EO modulation technology offers numerous advantages, such as high efficiency, good stability, a quick response time, and inertia-free characteristics. In this paper, we summarize the research progress of KTN series crystals systemically, including the theoretical exploration on quadratic EO effect, solid-melt crystal growth technique, comprehensive physical characterization, new physical effect and mechanisms exploration, new EO devices development and design. The EO modulation technique based on the Kerr effect of KTN series crystal offers obvious advantages in reducing the drive voltage and device size, which could better meet the developmental needs of future lasers with a wide wavelength, miniaturization, and integration. This may provide theoretical guidance and an experimental basis for the design and development of new EO crystal devices and promote the development of laser technology.