Growth, Structure, and Dielectric and Optics Properties of a Novel Optical Crystal with High Optical Nonlinearity

Abstract

In this study, a new class of organic salt nonlinear optical (NLO) crystals, 2-HDSAI and HDSAI, were synthesized and grown by designing and adjusting the methyl position on the receptor. Single-crystal XRD analysis confirms that the crystal belongs to monoclinic group P21. Among them, the HDSAI crystal has second harmonic generation (SHG) activity, and the maximum powder SHG is about 0.7 times that of OH1. The maximum nonlinear optical coefficient of the crystal is d11 = 62 pm/V @1064 nm by theoretical calculation. The HDSAI single crystal was successfully grown by the slow cooling method. Through the study of the optical and dielectric properties of the crystal, the results showed that the newly designed crystal has high transmittance (>75%) and low dielectric constant (εr ≈ 2). The thermal property test shows that the crystal has high thermal stability.