Nonlinear optical single crystal of bis 15-crown-5-ether (C₁₀H₂₀O₅) cadmium tri potassium thiocyanate was grown by slow evaporation technique. Parameters like solubility and growth rate play a vital role on the growth of thiocyanate family crystal. Furthermore, single crystal X-ray diffraction patterns provide detailed information about the lattice dimensions, crystal symmetry, bond length and bond angle, etc. This study reveals that title structure is monoclinic with a space group of P2_1/n. The lower cut-off wavelength of the sample was found to be 261 nm with optical band gap of 2.33 eV, which was calculated from UV–vis-NIR spectroscopy by Tauc’s relation. The grown crystal functional groups were identified and compared with FT-IR and micro-Raman spectroscopy. Additionally, dielectric, thermal, and mechanical properties of as-grown crystals are analyzed by the dielectric constant (ε_r) with dielectric loss (tanδ), decomposition temperature, hardness (H_V), and Mayer’s index (n) number. Third-order nonlinear optical coefficients (χ³) are determined by using Z-scan studies, and they play a curial role in the field of photonic device fabrication.

采用慢蒸发技术生长了双15冠5醚(C ₁₀ H ₂₀ O ₅ )硫氰酸镉三钾非线性光学单晶。溶解度和生长速率等参数对硫氰酸盐家族晶体的生长起着至关重要的作用。此外，单晶X射线衍射图提供了有关晶格尺寸、晶体对称性、键长和键角等的详细信息。本研究表明标题结构是单斜晶系，空间群为P2 1 / _n。发现样品的下限截止波长为 261 nm，光学带隙为 2.33 eV，这是根据 Tauc 关系从 UV-vis-NIR 光谱计算得出的。生长的晶体官能团被鉴定并与 FT-IR 和显微拉曼光谱进行比较。此外，通过介电常数 ( ε _r ) 和介电损耗 (tan δ )、分解温度、硬度 ( H _V ) 和迈耶指数 ( n ) 来分析生长晶体的介电​​、热和机械性能。三阶非线性光学系数（χ3）是通过Z扫描研究确定的，它们在光子器件制造领域发挥着重要作用^。