Surface plasmon devices for applications in communication and signal processing

表面等离子激元（SPPs）是一种在良好金属表面与传导电子振荡耦合的电磁波。表面极化子本质上是一个二维激发，SPPs可以将光信号的处理问题从三维减少到二维。这大大简化了它，并引入了利用这些波在纳米结构表面和薄膜上的特性进行信号调理和控制的额外机会。基于spp的应用可以为未来多波长光网络中信号处理应用的新器件奠定基础。随着这些网络向非线性和量子极限发展，需要新的设备功能来支持这些网络技术，并且这些设备必须紧凑和可集成。所需的功能是：可调的色散特性，用于将携带信号的数据解复用和路由到不同的网络节点；极化选择特性-用于极化复用，以增加数据量并减少信道之间的非线性相互作用；需要快速、高对比度的通断传递功能的光开关；自适应信号再生（包括3R重塑，重新定时和重新放大以及2R变体-执行重新整形而不重新定时），用于消除任何获得的非线性和噪声损伤，因为通道在网络中动态分配和路由。目前，这些功能大多需要离散的、大块的电子和光纤组件来实现。如果所有这些都能在一个紧凑的可集成器件中实现，理想情况下还带有一些光学增益，那将是非常吸引人的。这可能是可能的，如果表面等离激元极化为基础的效应部署，允许实现新的无源和有源光子器件，如可调谐波长和偏振选择结构，如果适当的设计可以实现。在这里，我们首次展示和研究了光学网络中光子元件的基本工作原理，其功能是由纳米结构金属表面和薄膜上表面等离激元极化子波的特殊性质所支撑的。偏振和波长敏感的应用，以及用于放大SPP信号的有源设备将被研究，用于通信和信号处理。

Surface plasmon polaritons (SPPs) are electromagnetic waves on a surface of good metals coupled to oscillations of conduction electrons. The surface polariton is intrinsically a two-dimensional excitation, and SPPs can be used to reduce the problem of optical signals' manipulation from three to two dimensions. This significantly simplifies it and introduces additional opportunity for signal conditioning and control using properties of these waves on nanostructured surfaces and thin films. The SPP-based applications can form the basis of new devices for signal processing applications in future multiwavelength optical networks. As these networks evolve towards the nonlinear and quantum limits, new device functionalities to support these network technologies are required, and these devices must be necessarily compact andintegrable. The functionalities required are: tuneable dispersive properties for demultiplexing and routing of data carrying signals to different network nodes; polarization-selective properties - for polarization multiplexing to increase the datarates and decrease nonlinear interaction between channels; optical switching which requires a fast, high-contrast on-off transfer function; adaptive signal regeneration (both 3R -reshaping, retiming and re-amplification and the 2R variant - which perform re-shaping without re-timing) for undoing any acquired non-linear and noise impairments as channels are dynamically allocated and routed around the network. Currently most of these functionalities require discrete, bulk electronic and fibre components to realise. It is very appealing if all of these could be implemented in a single compact and integrable device, ideally with some optical gain. This may be possible if surface plasmon polariton-based effects are deployed, which allow to achieve novel passive and active photonic devices such as tuneable wavelength and polarisation selective structures, if appropriate designs can be realised. Here we propose to demonstrate and investigate, for the first time, the basic principles of operation of photonic elements for optical networks with functionality underpinned by particular properties of surface plasmon polariton waves on the nanostructured metal surfaces and thin films. Polarisation and wavelength sensitive applications as well as active devices for amplification of SPP signals will be investigated, for applications in communications and signal processing.