High Numerical Aperture Hexagonal Stacked Ring-Based Bidirectional Flexible Polymer Microlens Array
High Numerical Aperture Hexagonal Stacked Ring-Based Bidirectional Flexible Polymer Microlens Array
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DOI：
10.1021/acsnano.7b00211
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发表时间：
2017-03-01
期刊：
影响因子：
17.1
通讯作者：
Butt, Haider
中科院分区：
文献类型：
--
作者：
Ahmed, Rajib;Yetisen, Ali K.;Butt, Haider
能够衍射/聚焦窄带光的柔性印迹光子纳米结构在光学透镜、滤光片、可调谐激光器、显示器和生物传感方面具有潜在的应用前景。通过全息和卷对卷印刷的纳米光子结构可以降低制造的复杂性和费用，并使大规模生产成为可能。在这里，通过全息和提升工艺将堆叠环阵列的三维光子纳米结构印迹在聚对苯二甲酸乙酯（PET）衬底上的丙烯酸酯聚合物（AP）上，以创建微透镜阵列（MLA）。阵列的表面结构由圆形无阶梯金字塔组成，重复图案呈六边形排列。在柔性AP PET衬底上制备的叠层环基MLA （SMLA）具有良好的双向光聚焦性能，最大数值孔径（NA = 0.60）和合理的填充系数。纳米结构在远场产生了有序的六边形聚焦衍射图，并通过角度分辨实验测量了功率强度。不同的纳米级尺寸（宽度和高度）以及不同的纳米级步数导致不同的光子带隙，阵列产生与距离相关的窄带光聚焦。通过文本、图像和全息投影实验验证了SMLA的有效性。预计在柔性基板上的双向印迹SMLA可能会在光学系统，显示器和便携式传感器中找到应用。
Flexible imprinted photonic nanostructures that are able to diffract/focus narrow-band light have potential applications in optical lenses, filters, tunable lasers, displays, and biosensing. Nanophotonic structures through holography and roll-to-roll printing may reduce fabrication complexities and expenses and enable mass production. Here, 3D photonic nanostructures of a stacked ring array were imprinted on acrylate polymer (AP) over poly (ethylene terephthalate) (PET) substrate through holography and lift-off processes to create a microlens array (MLA). The surface structure of the array consisted of circular nonostepped pyramids, and repeated patterns were in hexagonal arrangements. Stacked-ring-based MLA (SMLA) on a flexible AP PET substrate showed efficient bidirectional light focusing and maximum numerical aperture (NA = 0.60) with a reasonable filling factor. The nanostructures produced a well-ordered hexagonally focused diffraction pattern in the far field, and power intensities were measured through angle-resolved experiments. The variation of nanostep dimensions (width and height) and the number of steps resulted in different photonic bandgaps, and the arrays produced distance dependent narrow-band light focusing. The validation of the SMLA was demonstrated through the text, image, and hologram projection experiments. It is anticipated that imprinted bidirectional SMLA over flexible substrates may find applications in optical systems, displays, and portable sensors.