Daengngam Chalongrat, Kandas Ishac, Ashry Islam, Wang Anbo, Heflin James R, Xu Yong
Opt Express. 2015 Mar 23;23(6):8113-27. doi: 10.1364/OE.23.008113.
We develop and characterize a UV ablation technique that can be used to pattern soft materials such as polymers and nonlinear molecules self-assembled over silica microstructures. Using this method, we fabricate a spatially periodic coating of nonlinear film over a thin silica fiber taper for second harmonic generation (SHG). Experimentally, we find that the second harmonic signal produced by the taper with periodic nonlinear coating is 15 times stronger than the same taper with uniform nonlinear coating, which suggests that quasi-phase-matching is at least partially achieved in the patterned nonlinear silica taper. The same technique can also be used to spatially pattern other types of functional nanomaterials over silica microstructures with curved surfaces, as demonstrated by deposition of gold nanoparticles in patterned structures.
我们开发并表征了一种紫外烧蚀技术，该技术可用于对诸如聚合物和自组装在二氧化硅微结构上的非线性分子等软材料进行图案化处理。使用这种方法，我们在细二氧化硅光纤锥上制备了用于二次谐波产生（SHG）的非线性薄膜的空间周期性涂层。通过实验，我们发现具有周期性非线性涂层的光纤锥产生的二次谐波信号比具有均匀非线性涂层的相同光纤锥强15倍，这表明在图案化的非线性二氧化硅光纤锥中至少部分实现了准相位匹配。如在图案化结构中沉积金纳米颗粒所证明的那样，相同的技术还可用于在具有曲面的二氧化硅微结构上对其他类型的功能纳米材料进行空间图案化。
