Tapered Semiconductor Fibres for Nonlinear Photonics Applications

半导体光子学是一个正在给现代光电子器件的未来带来革命性变化的领域。虽然半导体材料通常与电子功能有关(例如，使用半导体微电子处理器的流行设备包括手机、计算机和数字无线电)，但到目前为止，许多重要的光子设备已被演示使用芯片上的基于平面的衬底，包括硅激光器和锗光电探测器。然而，最近，将半导体材料纳入光纤核心引起了人们的极大兴趣，因为它提供了一个独特的机会，可以将这项技术与数据传输网络中使用的现有硅纤维基础设施完全集成。与芯片上开发的器件相比，光纤化半导体器件具有一些显著的优势，例如简单、低成本的制造(即，不需要基于数百万美元的净室光刻)以及坚固和多功能的波导几何结构。此外，可结合到光纤几何结构中的半导体材料的宽(可见光到远红外)光学透明度确保了它们的应用将远远超出光通信，扩展到医学、传感、光谱和安全监测等学科。本提案中描述的工作旨在将这一令人兴奋的新半导体光纤平台与一项关键的波导技术：锥形光纤相结合。传统的锥形二氧化硅光纤沿长度具有不同的波导尺寸，已被用于大量应用，如光信号处理、超连续谱产生、遥感以及器件之间的优化模式耦合。这些结构的扩展将把具有丰富光电子功能的半导体材料引入锥形纤芯中，这将为半导体光波导的优化提供新的设计灵活性。因此，这项工作的主要目标将是开发制造高质量锥形半导体光纤结构的程序，并展示其在非线性光子应用中的潜力。这一高度创新的项目有可能导致许多技术颠覆性全光纤光电子器件的开发，例如用于医疗保健的超小型宽带中红外激光光源、用于化学分析的频率梳以及用于超高速通信的高度非线性光学耦合器和开关。

Semiconductor photonics is a field that is currently revolutionizing the future of modern optoelectronic devices. Although semiconductor materials are more commonly associated with electronic functionality (e.g., popular gadgets that use semiconductor microelectronic processors include cell phones, computers, and digital radios), to date a number of important photonic devices have been demonstrated using planar based substrates on a chip including silicon lasers and germanium photodetectors. More recently, however, the incorporation of semiconductor materials into the core of optical fibres has generated much interest as it provides a unique opportunity to completely integrate this technology with existing silica fibre infrastructures used in data transmission networks. Fiberized semiconductor devices offer some notable advantages over those developed on-chip such as simple, low cost fabrication (i.e., no need for multimillion dollar cleanroom based lithography) and robust and versatile waveguide geometries. Furthermore, the wide (visible to far-infrared) optical transparency of the semiconductor materials that can be incorporated into the fibre geometry ensures that their applications will extend far beyond optical communications to disciplines such as medicine, sensing, spectroscopy and security monitoring.The work described in this proposal seeks to combine this exciting new semiconductor fibre platform with a key waveguide technology: tapered optical fibres. Conventional tapered silica fibres, which have varying waveguide dimensions along the length, have been exploited for a wealth of applications such as, optical signal processing, supercontinuum generation, remote sensing, as well as for optimized mode coupling between devices. The extension of these structures to incorporate semiconductor materials with rich optoelectronic functionality into the tapered cores will present new degrees of design flexibility for the optimization of semiconductor optical waveguides. The primary goal of this work will thus be to develop the procedures for the fabrication of high quality tapered semiconductor fibre structures and to demonstrate their potential for nonlinear photonic applications. This highly innovative project has the potential to lead to the development of a number of technologically disruptive all-fibre optoelectronic devices, for example, ultra-compact broadband mid-infrared laser sources for healthcare, frequency combs for chemical analysis, and highly nonlinear optical couplers and switches for ultrafast telecommunications.