Research Progress on Nonlinear Optical Crystals in the Chalcogenide System

Author of the article:WU Xiaowen1 , GONG Chunjuan1 , WU Kui2

Author's Workplace：1. School of Resources and Environmental Engineering, Shandong Agriculture and Engineering University, Jinan 250100, China; 2. College of Chemistry and Environmental Science, Hebei University, Baoding 071002, China

Key Words：chalcogenide; nonlinear optical crystal; crystal structure design; structure-performance relationship

Abstract：Recently, nonlinear optical (NLO) crystals are the important media for the development of infrared (IR) laser technology. Chalcogenides exhibiting the large NLO coefficients and wide IR transmission ranges have become the main system for the exploration of new IR NLO crystals, such as commercial AgGaS2 and AgGaSe2. However, commercial crystals possess the low laser damage thresholds (LDTs) that further limit their wide application regions. Thus, exploration of new IR NLO chalcogenides with wide bandgaps and large NLO effects has become the research hotspot. Recent effective method is to improve the performances through the regulation of crystal structures that includes the following methods: ①introducing the alkali or alkaline earth metals into structures to regulate the optical bandgaps; ②incorporation of IIB cations with d10 configuration-centered tetrahedra as NLO active units; ③mixed-anions(O/S or halogen /S) regulating the material performances. In this paper, we have summarized the above-mentioned design ideas and the inherent structure-performance relationship in chalcogenides, which offers the good guidance for future design of new materials in the chalcogenide system.