Metal Chalcogenides: A Rich Source of Nonlinear Optical Materials

TLDR: In this paper, the authors review the recent developments in nonlinear optical (NLO) phenomena such as second harmonic and difference frequency generation (SHG and DFG), which are effective at producing a coherent laser beam in difficult to reach frequency regions of the electromagnetic spectrum.

Abstract: Materials chemistry and the pursuit of new compounds through exploratory synthesis are having a strong impact in many technological fields. The field of nonlinear optics is directly impacted by the availability of enabling materials with high performance. Nonlinear optical (NLO) phenomena such as second harmonic and difference frequency generation (SHG and DFG, respectively) are effective at producing a coherent laser beam in difficult to reach frequency regions of the electromagnetic spectrum. Such regions include the infrared (IR), far-infrared, and terahertz frequencies. High performance NLO crystals are critical for applications utilizing these coherent light sources, and new materials are continuously sought for better conversion efficiency and performance. The class of metal chalcogenides is the most promising source of potential NLO materials with desirable properties particularly in the IR region where most classes of materials face various fundamental challenges. We review the recent developments...