Photonic Ultra-high-Q REsonators (PURE)

光子超高 Q 谐振器 (PURE)

• 批准号: EP/Z531169/1
• 负责人: James Gates
• 金额: $ 162.47万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FZ531169%2F1
• 关键词: Photonic; Ultra; REsonators; PURE

Photonic ring resonators are miniature optical waveguiding structures that enable light to reach very high intensities in closed, circular paths. The loop structure and wave nature of light results in interference of the field such that the system becomes highly resonant with a repeated pattern. Each ring supports a comb of highly defined, specific frequencies of light, the spacing between which depends on the optical path length of the ring. In devices with a high-quality factor (high-Q), the optical circulating power can build up from a small milliwatt input signal to reach kilowatts of circulating power. The small, guided area of these devices results in immense power densities, permitting non-linear optical effects at remarkably low powers, despite the host material having low intrinsic non-linear properties. However, the achievable quality (Q) of such resonators has so far been limited by the losses caused by the absorption and scattering of light by the materials and structures used to fabricate the ring.The last 20 years have enabled significant progress in integrated photonics (optical circuits that guide and manipulate light analogous to the microchip in electronics), including the reduction of loss. Refined processes using CMOS-based cleanroom techniques have allowed researchers to improve optical transmission from 10% per metre to approximately 99.9% per metre in miniaturised optical chips. This has enabled the fabrication of optical microresonators with ultra-high-Q factors (over 100 million). These wafer-based devices form key components in advanced integrated photonic circuits for narrow linewidth lasers and frequency combs. The first generation of these devices has enabled compact systems for radar as well as for precision timing and navigation.Despite significant progress in the field, waveguide loss in state-of-the-art integrated photonics devices has plateaued at 100x higher losses than those readily achieved in standard telecoms optical fibre used for long-haul broadband internet. This limit is not fundamental but technological, and if fibre-like losses could also be achieved in an integrated photonics package, this would enable a new generation of applications and improvements in performance. These include compact, robust gyroscopes and low-power frequency combs for navigation and precision timing, ultra-narrow linewidth lasers (mHz to Hz), and advanced photonic components for telecommunication networks.This proposal seeks to combine the benefits of optical fibre fabrication approaches and material science developed over the past 50 years with the latest state-of-the-art CMOS fabrication techniques used for integrated optics. We aim to develop a manufacturing technique that will produce integrated ring resonator devices with the highest Q ever achieved. Using flame hydrolysis deposition and other standard optical fibre manufacturing techniques, we will develop ultra-pure glass layers to negate absorption losses. In particular, we will focus on high phosphorus and germanium doping, which we have shown can lead to dramatically better uniformity during our recent Caltech-Southampton DARPA seed project. We will use optical fibre manufacturing techniques to reduce loss from absorbed hydrogen and develop diffusion and reflow processes to remove waveguide interface and scattering losses.Our ambition is to develop the foundations for a scalable manufacturing process for the next generation of ultra-high-Q micro-ring resonators. These devices will enable a range of new technologies, including rugged miniature gyroscopes for navigation, combs for precision timing in data networks and optical sources for quantum technologies.

光子环形谐振器是微型光学波导结构，其使得光能够在封闭的圆形路径中达到非常高的强度。光的环结构和波性质导致场的干涉，使得系统变得与重复图案高度共振。每个环都支持高度定义的特定频率的光梳，光梳之间的间距取决于环的光路长度。在具有高品质因数（高Q）的设备中，光循环功率可以从小毫瓦输入信号积累到达到千瓦的循环功率。这些器件的小的引导区域导致巨大的功率密度，允许在非常低的功率下的非线性光学效应，尽管主体材料具有低的固有非线性特性。然而，到目前为止，这种谐振器的可实现质量（Q）受到用于制造环的材料和结构对光的吸收和散射所造成的损失的限制。过去20年，集成光子学（类似于电子学中的微芯片，引导和操纵光的光学电路）取得了重大进展，包括减少损失。使用基于CMOS的洁净室技术的精细工艺使研究人员能够将光学芯片的光传输从每米10%提高到每米约99.9%。这使得具有超高Q因子（超过1亿）的光学微谐振器的制造成为可能。这些基于晶片的器件构成了窄线宽激光器和频率梳的先进集成光子电路的关键部件。这些器件的第一代产品已使雷达以及精密定时和导航系统变得更加紧凑。尽管在该领域取得了重大进展，但最先进的集成光子器件中的波导损耗已经达到稳定水平，比用于长距离宽带互联网的标准电信光纤中的损耗高出100倍。这种限制不是根本性的，而是技术性的，如果在集成光子封装中也可以实现类似光纤的损耗，这将实现新一代的应用和性能改进。这些包括用于导航和精确定时的紧凑、坚固的陀螺仪和低功率频率梳、超窄线宽激光器（mHz至Hz）以及用于电信网络的先进光子元件。该提案旨在将过去50年来发展的光纤制造方法和材料科学的优点与用于集成光学的最新最先进的CMOS制造技术联合收割机结合起来。我们的目标是开发一种制造技术，将生产集成的环形谐振器设备具有有史以来最高的Q。使用火焰水解沉积和其他标准的光纤制造技术，我们将开发超纯玻璃层，以消除吸收损失。特别是，我们将专注于高磷和锗掺杂，我们已经证明，这可以导致显着更好的均匀性，在我们最近的加州理工学院-南安普敦DARPA种子项目。我们将使用光纤制造技术来减少吸收氢的损耗，并开发扩散和回流工艺来消除波导接口和散射损耗。我们的目标是为下一代超高Q微环谐振器的可扩展制造工艺奠定基础。这些设备将使一系列新技术成为可能，包括用于导航的坚固微型陀螺仪，用于数据网络精确计时的梳子以及用于量子技术的光源。