Lithium Niobate (LiNbO₃; LN) nanoparticles were dispersed into a polymer matrix, poly(methyl methacrylate) (PMMA) to prepare an organic–inorganic hybrid LN/PMMA nanocomposites. When no electric field was applied during dispersion, the polar LN nanoparticles remain randomly oriented in the PMMA and unpoled nanocomposite is obtained. In this work, poled LN/PMMA nanocomposites were prepared by applying an electric field of varying strength and used to investigate its influence on the second harmonic generation (SHG) properties (λ = 532 nm) using the fundamental laser (λ = 1064 nm). Since the electric field orients the dipoles of the LN nanoparticles inside the PMMA matrix in the direction of the field, a maximum was observed in the SHG signal as a function of electric field strength. The SHG from the differently poled nanocomposite was investigated as a function of LN nanoparticle concentration, fundamental laser energy, and sample thickness. The trend in SHG is explained and the role of induced and spontaneous polarizations in the SHG generation has been specifically highlighted. It has been observed that the effect of electric field on the SHG properties of the nanocomposite was observed only when the factors contributing to the loss of SHG signal are insignificant.

铌酸锂（铌酸锂₃ ; LN）纳米粒子分散到聚合物基体，聚（甲基丙烯酸甲酯）（ PMMA ），以制备有机-无机混合LN / PMMA纳米复合材料。当在分散过程中未施加电场时，极性LN纳米颗粒在PMMA中保持随机取向，并获得了未极化的纳米复合材料。在这项工作中，通过施加变化强度的电场制备了极化的LN / PMMA纳米复合材料，并使用 基波激光（λ = 532 nm）来研究其对二次谐波产生（SHG）特性（λ = 532 nm）的影响。 = 1064 nm）。由于电场使PMMA基质内部的LN纳米粒子的偶极子沿电场方向取向，因此在SHG信号中观察到最大值是电场强度的函数。研究了来自不同极化纳米复合材料的SHG与LN纳米粒子浓度，基本激光能量和样品厚度的关系。解释了SHG的趋势，并特别强调了感应极化和自发极化在SHG生成中的作用。已经观察到，只有当影响SHG信号损失的因素不明显时，才观察到电场对纳米复合材料的SHG性质的影响。