Metal‐Based Quadratic Nonlinear Optical Materials

Abstract

Nonlinear optical (NLO) materials have been the focus of intensive investigations for several decades from both the fundamental and practical points of view for their possible applications in the domain of optoelectronics and photonics. NLO materials can be used to manipulate optical signals, and when light interacts with such materials the incident light can be changed and new electromagnetic field components generated. NLO materials have potential applications in optical signal processing, frequency generation such as second and third harmonic generation (SHG and THG, respectively), and can also contribute to optical data storage and image processing. NLO activity can be found in inorganic crystals, such as LiNbO3, and also in organic materials. The latter have attracted great interest owing to their fast and large nonlinearities, their inherent tailorability, which allows fine tuning of the NLO properties, and to their compatibility with polymer matrices. About twenty years ago, the field of NLO was extended to molecular materials featuring organometallic and coordination complexes.