Digital imaging enhanced by plasmon resonance elements

在这个项目中，我们将结合牛津大学的CMOS成像仪设计技能和夏普欧洲实验室的薄膜技术，以及格拉斯哥大学的纳米制造和纳米光学专业知识，首次实现用于成像和显示的等离子体增强技术。所提出的技术可以在标准技术表面的单一制造层中提供波长和偏振控制。目前的技术依赖于多层处理来实现较弱的效果，这是一个重大的进步。由于介质色散关系，金属薄膜表面会发生光学共振。这种现象导致表面等离子体共振（SPR）。表面等离子体是引起表面电子密度波动的非辐射电磁表面波。这种现象最简单的利用是在薄膜中，其中色散关系接近共振，导致传播光波的电场增强。表面不均匀性，例如在金属表面故意制造的周期性波动，被用来改善光与等离子体激元[1]的耦合，从而增加增强。最近的研究表明，从胶体悬浮液到直写光刻技术，纳米颗粒结构可以进一步增强小结构的SPR。CMOS集成电路现在是光学成像的主导技术，包括数码相机、显微镜和一系列光学仪器。同样，有源显示技术在工业和商业领域已成为主导和广泛应用。这些电子器件结合了高性能和低成本，还使设计人员能够在与成像传感器相同的基板上实现信号处理功能，以降低成本，像素尺寸和功耗。然而，目前的技术存在许多缺陷，限制了传统市场的发展。此外，在使核心技术能够扩展其功能并因此在新兴市场中使用方面所做的工作很少。该项目的目的是利用新兴的等离子体领域来研究在硅铸造厂使用后端（BEOL）处理的潜力，从而增强和多样化电子光学探测器、成像仪和显示器的能力。

In this project we will combine the CMOS imager design skills at Oxford University and the thin-film technology of Sharp Laboratories Europe with the nanofabrication and nano-optics expertise at Glasgow University to, for the first time, implement plasmon enhanced technologies for use in imaging and displays. The proposed technology can provide both wavelength and polarisation control in a single fabricated layer on the surface of otherwise standard technologies. This is a major step-forward from present day technologies that rely on multiple layers of processing to achieve less powerful effects.Optical resonances occur at the surface of metal films due to the dielectric dispersion relation. This phenomenon leads to surface plasmon resonances (SPR). Surface plasmons are non-radiative electromagnetic surface waves that cause fluctuations in the surface electron density. The simplest exploitation of this phenomenon is in thin films where the dispersion relation is close to resonance, leading to the enhancement of the electric field of a propagating light wave. Surface inhomogeneity, such as a deliberately-created periodic undulation on the metal surface, is used to improve the coupling of the light to the plasmons [1] hence increasing the enhancement. More recent work has shown how nanoparticle structures made by techniques ranging from colloidal suspensions to direct-write lithography can lead to further SPR enhancement in small structures.CMOS integrated circuits are now the dominant technology for optical imaging, including digital cameras, microscopes and a range of optical instruments. Similarly, active display technologies have become dominant, and widespread, in industrial and commercial sectors. These electronic devices combine high performance with low cost and also enable designers to implement signal processing functions on to the same substrate as the imaging sensor to reduce cost, pixel size and power consumption. However, current technologies suffer from a number of drawbacks that are limiting progress in traditional markets. Furthermore, little is being done to enable the core technology to expand its functionality, and hence use, in new and emerging markets. The aim of this project is to use the emerging field of plasmonics to study the potential for using back-end-of-line (BEOL) processing at the silicon foundry to enable both enhancement and diversification of the capabilities of electronic optical detectors, imagers and displays.