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.
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.
