Superior Infrared Nonlinear Optical Performance Achieved by Synergetic Functional Motif and Vacancy Site Modulations

Achieving large phase-matchable (PM) nonlinear optical (NLO) efficiency and high laser-induced damage threshold (LIDT) in an infrared second-order NLO (IR NLO) material is the most crucial technical endeavor but the most challenging. A synergetic strategy of modulating NLO functional motifs and vacancy sites for excellent comprehensive performances is proposed. The application of such a strategy in salt-inclusion systems affords two chalcogenides [K4Cl][CdGa(9)Q(16)] (Q = S, 1; Se, 2), which possess the important merits of a practical IR NLO material, including large PM NLO efficiency (0.9 and 2.4 x AgGaS2) and high LIDTs (22.6 and 7.7 x AgGaS2). Remarkably, compound 2 has the strongest SHG intensity among all known PM salt-inclusion chalcogenides. In addition, the strategy also enhances the structural anisotropy and renders 2 the first PM one among all known NLO salt-inclusion selenides. This work provides a novel design approach of the IR NLO material much more superior than other unique modulations.

Automated summary

A synergistic strategy of modulating NLO functional motifs and vacancy sites has been proposed to achieve excellent comprehensive performances in IR NLO materials, leading to the development of practical IR NLO materials with large PM NLO efficiency and high LIDTs. This work presents a novel design approach superior to other unique modulations in the field of IR NLO materials.