Mid-Infrared GeRmAnium phoTonIcs fOr seNsing (MIGRATION)

第四类光子学是目前正在给现代光电设备的未来带来革命性变化的一个领域。到目前为止，人们的大部分注意力都集中在用于数据通信的近红外波长的硅基材料上，尽管最近在2-3um波段的一些演示包括拉曼和参数放大。将这些设备的工作范围扩展到中红外区域有许多优点，如较低的光学损耗和较高的非线性系数，这一领域的初步设备工作表明，与近红外设备相比，效率有所提高。此外，该波长系统支持许多重要的应用，如化学和生物传感、环境和有害物质监测、医药和工业过程控制。对于这些应用中的许多应用来说，最有效的波长波段是所谓的‘指纹’区域(&gt；8um)，在那里可以精确地识别许多分子物质。然而，由于硅的透明度只延伸到~8um，最近的关注转向了Ge(透明度范围2-15um)作为一种替代平台，以完全实现用于传感和其他生命科学应用的IV类设备的中红外能力。值得注意的是，与硅相比，锗在器件开发方面具有许多其他优势，例如更高的非线性系数、更好的载流子迁移率，以及实现基于锗合金的有源器件的潜力。该方案的工作建议为中红外第四类光子学从硅向锗平台的迁移奠定基础，目的是证明这一领域的新兴技术是未来可行的。因此，这项工作的主要成果之一将是确定高质量的锗衬底，其性能可与在1-3um制度下使用的成熟的绝缘体上硅晶片相媲美；这项任务将与我们的项目合作伙伴IQE共同完成，他们是英国先进半导体晶片制造的全球领先者。然后，该框架将用于展示一系列器件，如波导、耦合器、滤波器、放大器和调制器，这些器件将在扩展的波长范围内构成集成片上电路、系统和传感器的构建块。虽然该项目的主要重点是开发用于有毒物质检测的集成传感器，提高效率、紧凑性和稳健性，这是DSTL和其他国防和安全利益攸关方所需的，但通过瞄准能够执行一系列基本功能的设备，这些将与确保最大影响的各种应用相关。这一富有远见的研究计划处于这一令人兴奋的中红外第四类光子学新领域的前沿，因此有望提供许多颠覆性的中红外光子学解决方案。

Group IV photonics is a field that is currently revolutionizing the future of modern optoelectronic devices. So far most of the focus has been on silicon based materials at near-infrared wavelengths for use in data communications, though some more recent demonstrations in the 2-3um regime include Raman and parametric amplification. There are a number of advantages to extending the operational range of these devices into the mid-infrared regime such as lower optical losses and higher nonlinear coefficients, and preliminary device work in this area has shown improved efficiencies over their near-infrared counterparts. Moreover, this wavelength regime supports a host of important applications such as chemical and biological sensing, environmental and hazardous substance monitoring, medicine, and industrial process controls. The most efficient wavelength band for many of these applications is the so called 'fingerprint' region (>8um) where the precise identification of many molecular substances is possible. However, as the transparency of silicon only extends to ~8um, more recently attentions have been turning to germanium (transparency range 2-15um) as an alternative platform to fully realize the mid-infrared capabilities of group IV devices for sensing and other life science applications. Significantly, compared to silicon, germanium offers a number of other advantages in terms of device development such as even higher nonlinear coefficients, better carrier mobility, and the potential to realise active devices based on germanium based alloys. The work in this programme proposes to lay the foundations for a migration of mid-infrared group IV photonics from silicon to germanium-based platforms with the aim to future proof emerging technologies in this field. Thus, one of the main outcomes of this work will be to identify high quality germanium substrates that rival the performance of the well-established silicon-on-insulator wafers used over the 1-3um regime; a task that will be performed in conjunction with our project partners IQE who are the UK's global leaders in advanced semiconductor wafer fabrication. This framework will then be used to demonstrate a library of devices such as waveguides, couplers, filters, amplifiers and modulators that will form the building blocks of integrated on-chip circuits, systems and sensors over an extended wavelength regime. Although the primary focus of this project is the development of integrated sensors for toxic detection with improved efficiency, compactness, and robustness, which are required for DSTL and other defence and security stakeholders, by targeting devices that can perform a range of basic functions, these will be relevant to a variety of applications ensuring maximal impact. This visionary programme of research is at the forefront of this exciting new area of mid-infrared group IV photonics and thus promises to deliver a number of disruptive mid-infrared photonics solutions.