Exploiting tailored disorder in dielectric nanosurfaces to maximize their information capacity

介电纳米表面通过在空间上确定性地改变入射场的相位/幅度来在入射场上留下印记信息。当强散射物体由高介电常数材料制成时，效率最高。如果工作在它们的二元点上，就实现了完美的传输。这开启了照明和成像设备、超薄显示技术、波前操纵和光束整形等领域的大量令人兴奋的应用。然而，没有免费的午餐，控制光线的能力是以显著的远程互动为代价的。如果这些散射体是定期排列的，这将禁止对即使是相当数量的信息进行编码。在第一个SPP资助期，我们探索了这些散射体排列的无序如何抑制这种远程相互作用，并研究了无序对纳米表面光学响应的影响。在共同的努力下，我们掌握了无序纳米表面的基本性质，并揭开了一些意想不到的现象，例如无序导致纳米表面响应的相变。总而言之，我们的工作为第二个资助期的大量研究打开了大门。我们在第二个资助期的研究线索的共同主题是最大化编码到我们纳米表面的信息能力。这既涉及在纳米表面的相同区域内编码的独立通道的数量，也涉及在每个通道中编码的信息密度。在第一个研究链中，我们集中于波前整形纳米表面，其中信息密度通过显式地利用无序来增强。这种无序在空间上被量身定做，以调整透射光的局部幅度和相位。这种在单一材料层内的完全控制将实现精确而不仅仅是近似的全息图。我们还打算利用光谱/角度色散响应来实现不同波长/照明场的全息图。在第二项研究中，这些能力被用来在选定的示范者中定制扩散散射。我们研究了以连续方式改变入射光方向的装置，并探测纳米表面在多大程度上可以模拟普通3D随机介质的响应。这将回答来自大容量媒体的信息可以被编码到哪个微小空间的问题。在第三个研究线索中，我们质疑我们可以在多大程度上从自然中学习，以感知提供所需响应的纳米表面。在所有方面，但特别是在这最后一条研究线上，我们期望与最高人民大会党的其他合作伙伴共同努力，为其总体目标作出贡献。我们在无序纳米表面中研究光传播的工作结合了科学挑战、智慧之美和实用价值。我们可以放心地期待，我们的洞察力将同时为光学、光子学和材料科学的更广泛发展做出贡献。

Dielectric nanosurfaces imprint information onto an incident field by spatially varying its phase/amplitude deterministically. The highest efficiency is achieved if the strongly scattering objects are made from high-permittivity materials. If operated at their duality point, perfect transmission is achieved. This unlocks a plethora of exciting application in lighting and imaging devices, ultra-thin display technologies, for wavefront manipulation, and beam shaping. However, there is no free lunch and the ability to control light disruptively comes at the expense of a heavily pronounced long-range interaction. This prohibits to encode even a decent amount of information if these scatterers were arranged periodically. In the first SPP funding period, we explored how disorder in the arrangement of these scatterers suppresses this long-range interaction and studied the impact of disorder on the optical response of nanosurfaces. In joint efforts, we mastered the basic properties of disordered nanosurfaces and unravelled unexpected phenomena, e.g. a disorder induced phase transition in the response of the nanosurface. Altogether, our work opens the doors for a plethora of investigations in the second funding period.The common theme of our research strands in the second funding period is the maximization of the information capacity encoded into our nanosurfaces. This concerns both the number of independent channels encoded within the same area of the nanosurface but also the information density encoded in each channel.In a first research strand, we concentrate on wavefront shaping nanosurfaces where the information density is enhanced by explicitly exploiting disorder. The disorder is spatially tailored to adjust the local amplitude and phase of the transmitted light. This full control within a single material layer will implement exact and not just approximate holograms. We also aim to exploit the spectral/angular dispersive response to implement holograms at different wavelengths/illumination fields. In a second research strand, these abilities are used to tailor the diffusive scattering in selected demonstrators. We study devices that redirect the incident light in a continuous fashion and probe to which extent a nanosurface can mimic the response from an ordinary 3D random media. This will answer the question into which tiny space the information from a bulk media can be encoded.In a third research strand, we question to which extent we can learn from nature to perceive nanosurfaces that offer a desired response. In all but particularly in this last research strand we expect to work together with other partners from the SPP and to contribute to its overarching goals. Our work on studying light propagation in disordered nanosurfaces combines scientific challenge, intellectual beauty, and practical utility. We safely anticipate that our insights contribute simultaneously to the wider developments of optics and photonics and material sciences.