Nonlinear optical microscopy was employed to investigate the properties of microstructures of quinacridone, a hydrogen-bonded pigment, derivative of quinacridine. Recently, quinacridone hierarchical microstructures (μ-QNC) having different nature-inspired morphologies were reported, e.g. in the shape of hedgehogs formed by self-assembled nano-needles. We find that such microcrystals have structure-dependent linear optical properties and exhibit strong two-photon excited fluorescence when irradiated with a near-infrared femtosecond laser. μ-QNCs exhibit different nonlinear optical properties for different crystal structures, including the emergence of symmetry-forbidden second-harmonic generation.

非线性光学显微镜用于研究喹ac啶酮，氢键合颜料，喹r啶衍生物的微观结构的特性。近来，报道了具有不同的自然激发形态的喹ac啶酮分级微结构（μ-QNC），例如呈由自组装纳米针形成的刺猬的形状。我们发现，这种微晶具有与结构有关的线性光学特性，并在用近红外飞秒激光照射时表现出很强的双光子激发荧光。μ-QNC对不同的晶体结构表现出不同的非线性光学性质，包括出现对称对称的禁止二次谐波产生。