Collaborative Research: Novel Laser and Nonlinear Properties of Anderson Localization Optical Fibers

在过去的半个世纪里，光纤一直是许多技术进步的支柱。仅举一个例子，通过光纤的跨洋电信连接了世界上几乎所有的民族和文化。这些纤维将光限制在中心玻璃芯中，该玻璃芯由光学密度比周围玻璃包层更大的材料制成。本文提出的基础研究集中在一种新型光纤，它通过安德森定位来引导光。在这种纤维中，首先由PI和团队实践，由于菲利普安德森提出的诺贝尔奖获奖现象，内部随机微观结构引导光线。直接的好处是，光纤上的任何位置，而不仅仅是纤芯，都可以用来引导和控制光。这种安德森定位纤维具有许多其他新颖的特性，使其在基础科学探索和设备级应用中都具有吸引力。提出的研究将探索这些新型光纤的激光和非线性特性。器件研究包括用于成像和照明的超宽彩色光谱激光器的研究。成像可以受益于明亮的激光源；不幸的是，传统的激光器是单色的，而提出的激光器可以提供相当广泛的色域。还将研究用于安全通信和高速计算的可调谐量子相关光子对发生器，这是由随机底层结构的多样性提供的。除了新科学的进步之外，一个主要的成果将是使从事这个项目的研究生和本科生在跨学科的环境中接触到广泛的主题。这种对不同学科的广泛接触是培养未来高技能劳动力的平台。技术摘要：这个变革性的项目将对一种新型光纤进行深入研究，这种光纤不是在传统的芯包层设置中引导光，而是通过安德森定位，在这种定位中，光纤横向轮廓的任何位置都可以用来引导光。该研究特别关注这些新型光纤的激光和非线性特性，这些特性对基础科学探索和设备级实用和见解都有潜在的好处。本研究将揭示局域化本质及其与非线性相互作用的突出问题，并探讨安德森局域化对激光阈值行为、斜率效率、稳定性和频谱等特性的影响。相反，非线性和增益对局域化特性的影响将被探讨。在过去的六年里，人们对安德森定位光纤进行了探索，在波束复用、图像传输、波前整形、锐利聚焦和单光子数据打包等方面都有很大的前景。然而，关于这些光纤的光学特性仍然有许多悬而未决的问题必须首先解决。例如，将研究这些光纤中模式的相位和群速度的统计数据，以确定它们在光通信、量子信息处理、成像和照明以及医疗和工业应用的超短脉冲激光器方面的潜力。为了在高功率光纤激光器中的应用，我们将研究它们的激光特性和模态动力学。所提出的器件包括用于照明和成像的宽带低空间相干稀土掺杂光纤激光器，特别是在近红外光谱，超高功率掺镱光纤激光器，使用单链光纤的可调谐激光器，以及用于量子信息处理的通过四波混频的量子相关光子对的可调谐源。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Optical fibers have been the enabling backbone for many technological advancements over the last half-century. As just one example, transoceanic telecommunications via optical fibers connect nearly all the world's peoples and cultures. Those fibers confine light in a central glass core made from an optically denser material than the surrounding glass cladding. The proposed fundamental investigation here is focused on a novel class of optical fibers that guide light by means of Anderson localization. In such fibers, first brought to practice by the PI and team, an internal random microstructure guides the light due to a Nobel-Prize-winning phenomenon proposed by Phillip Anderson. The immediate advantage is that any location across the fiber, not just the core, can be used to guide and control light. Such Anderson localizing fibers have many other novel properties that make them attractive for both basic science exploration and device-level application. The proposed study will explore laser and nonlinear properties of these novel fibers. Device investigations include the study of ultra-broad color spectrum lasers for imaging and illumination. Imaging can benefit from bright laser sources; unfortunately, conventional lasers are single-colored and the proposed lasers can provide a considerably broader color gamut. Also to be studied are tunable quantum-correlated photon pair generators for secure communication and high-speed computation, afforded by the diversity of possibilities in the random underlying structure. In addition to the advancement of new science, a major outcome will be the exposure of the graduate and undergraduate students working on this project to a broad range of topics in an interdisciplinary environment. This broad exposure to different disciplines is a platform to train the highly skilled workforce of the future.Technical Abstract:This transformative program will provide an in-depth investigation of a novel class of optical fibers that guide light, not in a conventional core-cladding setting, but by means of Anderson localization, where any location across the transverse profile of the fiber can be used to guide light. The study is particularly focused on the lasing and nonlinear properties of these novel fibers with potential benefits to both basic science exploration and device-level utility and insights. The research will unravel outstanding problems on the nature of localization and its interaction with nonlinearity and to explore the impact of Anderson localization on laser characteristics such as threshold behavior, slope efficiency, stability, and frequency spectrum. Conversely, the impact of the nonlinearity and gain on localization properties will be explored. Anderson localization fibers have been explored over the past six years, and are quite promising for beam multiplexing, image transport, wave-front shaping, sharp focusing, and single-photon data packing. However, there are still many open questions regarding the optical properties of these fibers that must be addressed first. For example, the statistics of the phase and group velocities of the modes in these fibers will be explored to determine their potential for optical communications, quantum information processing, imaging and illuminations, and ultra-short-pulse lasers for medical and industrial applications. Their laser properties and modal dynamics will be studied for applications in high-power fiber lasers. Examples of the proposed devices include broadband low-spatial coherence rare-earth doped fiber lasers for illumination and imaging, especially in the near infrared spectrum, ultra-high power Ytterbium-doped fiber lasers, tunable lasers using a single strand of fiber, and tunable sources of quantum correlated photon pairs via four-wave mixing for quantum information processing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.