用于薄膜吸收增强的逆向设计与光学涡旋操控
Inverse design and optical vortex manipulation for thin film absorption enhancement
AI总结：
本研究展示了光学涡旋与薄膜吸收增强的相关性，通过逆向设计优化二维超薄吸收器，并引入OV circularity参数，揭示了高circularity局域OVs在优化纳米吸收器中的关键作用。
摘要：
光学涡旋具有快速变化的空间相位，以及围绕零光强点或线循环的光学能量。OV的操控为光学传感、通信和成像等领域提供了创新方法。在本研究中，我们展示了OVs与两类结构中吸收增强之间的相关性。首先，我们引入了一种简单的平面一维（1D）结构，利用两个相干光源操控OVs。该结构根据OVs的存在与否显示出最大6.05倍的吸收差异。即使是入射角的微小差异也会影响OVs的产生/湮灭，这意味着角光检测的高灵敏度。其次，我们应用逆向设计来优化二维（2D）完美超薄吸收器。优化的自由形态结构实现了99.90%的吸收率，而可制造的grating结构在775 nm波长下实现了97.85%。为了评估OV场及其对实现吸收增强的贡献，我们引入了一个新参数，即OV circularity。优化后的结构产生了大量OVs，最大circularity分别为95.37%（自由形态）和96.14%（grating），优于我们的1D结构。我们的研究揭示了高circularity局域OVs在优化纳米结构吸收器和器件中的作用，这些器件可用于光学传感、光通信及许多其他应用。
英文摘要：
Optical vortices (OVs) have rapidly varying spatial phase and optical energy that circulates around points or lines of zero optical intensity. Manipulation of OV offers innovative approaches for various fields, such as optical sensing, communication, and imaging. In this work, we demonstrate the correlation between OVs and absorption enhancement in two types of structures. First, we introduce a simple planar one-dimensional (1D) structure that manipulates OVs using two coherent light sources. The structure shows a maximum of 6.05-fold absorption gap depending on the presence of OVs. Even a slight difference in the incidence angle can influence the generation/annihilation of OVs, which implies the high sensitivity of angular light detection. Second, we apply inverse design to optimize two-dimensional (2D) perfect ultrathin absorbers. The optimized free-form structure achieves 99.90% absorptance, and the fabricable grating structure achieves 97.85% at 775 nm wavelength. To evaluate OV fields and their contribution to achieving absorption enhancement, we introduce a new parameter, OV circularity. The optimized structures generate numerous OVs with a maximum circularity of 95.37% (free-form) and 96.14% (grating), superior to our 1D structure. Our study reveals the role of high-circularity localized OVs in optimizing nano-structured absorbers and devices for optical sensing, optical communication, and many other applications.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
