Composite material hollow core fibres for active photonics

光纤构成了令人瞩目的20亿公里全球电信网络的物理层，目前以20马赫的速度分叉和扩展，即超过14000英尺/秒(来源：Corning.com)。它们也是激光、光学放大器、陀螺仪、气体或环境传感器等设备的基本组件，也是在本地连接设备和应用的一种手段。在过去20年中，光纤技术最重大的进步之一是实现了能够使用空气芯而不是玻璃在内部引导光的二氧化硅光纤。中空纤芯光子带隙光纤(HC-PBGFs)最早出现于20世纪90年代末。研究人员发现了非凡的物理学，证明了这些光纤能够传输高光功率、超短脉冲和波长区域，包括无法通过标准光纤传输的中红外区域。在这些波长区域内可以针对许多重要的应用，尤其是中红外光可以用于检测广泛的化学、生物或物理物种(例如识别表面上的爆炸物、环境中的有害空气污染物或患者呼吸中的生物标记物)。过去几年在中空纤维领域取得了巨大的进步，尤其是基于简单得多的光学设计与光子带隙光纤竞争的技术的发展，对于短波长和长波长传输，它们都更容易制造，并且已经证明，在光纤内传播的光和形成包层的二氧化硅之间的重叠大大减少。这种新型的空芯光波导称为反谐振光纤。在这项提案中，我们将展示一种基于复合材料中空纤芯光纤的创新波导平台，它不仅能够在较宽的波长范围内传输低衰减的光信号，而且还可以通过调制、放大或光产生和频率转换来主动管理和控制传输的信号。

Optical fibres form the physical layer of the remarkable >2 billion km long global telecommunications network, currently bifurcating and expanding at a rate >Mach 20, i.e. over 14000 ft/sec (source: Corning.com). They are also an essential component in devices such as lasers, optical amplifiers, gyroscopes, gas or environmental sensors, as well as a means to locally link devices and applications. One of the most significant advances in optical fibre technology over the last 20 years has been the realisation of silica fibres that are able to internally guide light using an air core rather than glass. Hollow Core Photonic Bandgap Fibres (HC-PBGFs) were first demonstrated in the late 1990s. Researchers uncovered remarkable physics, demonstrating that these fibres were able to transmit high optical powers, ultrashort pulses and wavelengths regions including the mid-IR which cannot be delivered through standard optical fibres. A number of important applications can be targeted within these wavelength regions and in particular mid-infrared light can be used to detect a wide range of chemical, biological or physical species (e.g. to identify explosives on surfaces, hazardous air pollutants in the environment, or biomarkers in the breath of a patient).The last few years have seen dramatic progress in the area of hollow fibres and in particular the development of a competing technology to photonic bandgap fibres based on a much simpler optical design, which are far easier to fabricate for both short and long wavelength transmission and have been demonstrated to have a greatly reduced overlap between the light travelling within the fibre and the silica forming the cladding. This novel form of hollow core optical waveguide is known as the anti-resonant fibre. In this proposal, we will demonstrate an innovative waveguide platform based on composite material hollow core fibres which are able not only to transmit optical signals with low attenuation over a broad wavelength range of operation, but can also actively manage and control the transmitted signals, through modulation, amplification or light generation and frequency conversion.