Fundamental Quantum Optics in Hollow-Core Photonic Crystal Fibers

空心光子晶体光纤中的基础量子光学

• 批准号: 1068865
• 负责人: Michael Raymer
• 金额: $ 68万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1068865&HistoricalAwards=false
• 关键词: Fundamental; Quantum; Optics; Hollow; Core

This program aims to develop a near-ideal material medium for generating and manipulating nonclassical states of light for fundamental studies in quantum information science. By ideal we mean photon-atom interactions in a system having isolated degrees of freedom that may evolve to become entangled among themselves without becoming entangled to any reservoir of unmonitored auxiliary systems. The system being developed is comprised of ultrahigh-density xenon gas confined to the interior of a hollow-core photonic crystal fiber (PCF), which can guide tightly focused light over several meters, enhancing the light-matter interaction. This system combines several outstanding properties, making it ideal for use as a medium for four-wave mixing interactions between light beams, including photon pair generation, mode entanglement, optical frequency comb generation, and soliton propagation. Being a fluid (at temperature 16 C and pressure 57 bar), near-critical Xe has variable density like a gas, but at the same time has a very high third-order optical nonlinearity -- approaching that of solid silica glass, which is the standard fiber-based medium now in wide use. Being an atomic gas, Xe has negligible levels of Raman and Brillouin scattering, which are severe impediments to current studies using silica as a nonlinear-optical medium. In the high-density Xe system we expect to see reduced noise signals and enhanced entanglement in photon generation, and reduced noise and enhanced quantum squeezing in frequency comb generation and soliton propagation, enabling deeper fundamental studies of these phenomena. Challenges include designing Xe-filled PCF to have the needed dispersion properties for phase matching the nonlinear-optical processes of interest. Such a new medium could find widespread use in the optical quantum-information community, and could transform our abilities to perform all-optical quantum-state generation and manipulation tasks.Quantum information technology aims to create, store, transmit, and process information in ways not possible using classical-physics-based techniques. For this we need "ideal interactions" between light and matter, with which to transfer information between two physical systems without having that information partially "leak" into the surroundings. Such leakage would destroy the quantum "integrity" of the systems (atoms or photons) being used to store and process the quantum information. Such ideal interactions are at the heart of proposed quantum optical technologies, such as secure long-distance communication and quantum computing using photon states. In order for such technologies to become useful, we need nearly ideal methods to prepare, control, and manipulate quantum states of photons and optical fields.For this purpose we are developing a unique optical material system -- high-density xenon gas confined to the interior of a hollow-core optical fiber -- which can guide tightly focused light over several meters, enhancing the light-matter interaction. Such a system is projected to enhance the interaction of light with xenon gas -- the most highly interacting of the nobel gases -- by several orders of magnitude compared with room-pressure gas in a standard gas cell. When intense laser light passes through such a gas, its frequency spectrum can be altered in a predictable way, generating many new frequencies, while maintaining the "integrity" of the quantum state of the light. This offers the possibility to create "quantum-entangled" states of many light waves having different frequencies. This interaction can also create quantum solitons, which are light pulses that travel in the xenon gas without becoming stretched in time, as usually occurs when light pulses propagate. Studying solitons can provide tests of the most sophisticated quantum field theories for describing the light-mater interaction.Quantum optics offers excellent opportunities to integrate research with science education. PhD students currently involved in the PI's research have contributed to the NSF's GK-12 Program, which pairs PhD students with high schools and middle schools, exposing their students to the idea of research as a career. High-school students, undergraduate students, Masters and PhD students, as well as visiting scientists, have all been involved in the groups' research in recent years. Students also participate as co-instructors of courses in a new Science Literacy Program at the University of Oregon, co-directed by the PI.

该项目旨在为量子信息科学的基础研究开发一种近乎理想的材料介质，用于产生和操纵光的非经典状态。所谓理想，我们指的是具有孤立自由度的系统中的光子-原子相互作用，这些系统可能会相互纠缠，而不会与任何不受监控的辅助系统纠缠在一起。正在开发的系统由被限制在空心光子晶体光纤（PCF）内部的超高密度氙气组成，它可以引导紧密聚焦的光超过几米，增强光与物质的相互作用。该系统结合了几个突出的特性，使其成为光束之间四波混合相互作用的理想介质，包括光子对的产生、模式纠缠、光频梳的产生和孤子传播。作为一种流体（温度16℃，压力57 bar），接近临界的Xe具有像气体一样的可变密度，但同时具有非常高的三阶光学非线性，接近固体硅玻璃的非线性，这是目前广泛使用的标准纤维基介质。作为一种原子气体，Xe的拉曼散射和布里渊散射水平可以忽略不计，这严重阻碍了目前使用二氧化硅作为非线性光学介质的研究。在高密度Xe系统中，我们期望在光子产生中看到噪声信号的减少和纠缠的增强，在频率梳产生和孤子传播中看到噪声的减少和量子压缩的增强，从而能够对这些现象进行更深入的基础研究。挑战包括设计充满xe的PCF，使其具有所需的色散特性，以匹配感兴趣的非线性光学过程。这种新介质可以在光学量子信息界得到广泛应用，并可以改变我们执行全光量子态生成和操作任务的能力。量子信息技术旨在以经典物理技术无法实现的方式创建、存储、传输和处理信息。为此，我们需要光与物质之间的“理想相互作用”，在两个物理系统之间传递信息，而不让信息部分“泄漏”到周围环境中。这种泄漏会破坏用于存储和处理量子信息的系统（原子或光子）的量子“完整性”。这种理想的相互作用是量子光学技术的核心，例如使用光子态的安全远程通信和量子计算。为了使这些技术变得有用，我们需要接近理想的方法来制备、控制和操纵光子和光场的量子态。为此，我们正在开发一种独特的光学材料系统——高密度氙气被限制在空心光纤的内部——它可以引导紧密聚焦的光超过几米，增强光与物质的相互作用。这样的系统预计将增强光与氙气体的相互作用，氙气体是诺贝尔气体中相互作用最强烈的气体，与标准气体池中的室温气体相比，其相互作用提高了几个数量级。当强激光穿过这种气体时，它的频谱可以以一种可预测的方式改变，产生许多新的频率，同时保持光的量子态的“完整性”。这提供了创造许多不同频率光波的“量子纠缠”状态的可能性。这种相互作用也可以产生量子孤子，这是光脉冲在氙气中传播而不会在时间上被拉伸，就像光脉冲传播时通常发生的那样。研究孤子可以为描述光-物质相互作用的最复杂的量子场论提供检验。量子光学提供了将研究与科学教育相结合的绝佳机会。目前参与PI研究的博士生为NSF的GK-12计划做出了贡献，该计划将博士生与高中和初中配对，让他们的学生接触到研究作为职业的想法。近年来，高中生、本科生、硕士生和博士生以及访问科学家都参与了这些团体的研究。学生们还作为共同讲师参加俄勒冈大学一个新的科学素养项目的课程，该项目由PI共同指导。