RUI: Coherence-Derived Light Fluctuations for Atomic Magnetometry

RUI：用于原子磁力测量的相干衍生光波动

• 批准号: 1506499
• 负责人: Stephen Tufte
• 金额: $ 19.5万
• 依托单位: Lewis and Clark College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1506499&HistoricalAwards=false
• 关键词: RUI; Coherence; Derived; Light; Fluctuations

Significant advancements in 21st century physics have relied on the discovery that properties of atoms are not fixed, but can be changed by interactions with laser light. The ability to understand and control these sensitive interactions is also the key to the creation of new atom-light based technologies. Some atom-light interactions are sensitive to the surrounding magnetic field. As an example, an atom is extremely selective about the precise colors of light it absorbs, but when it is placed in a magnetic field, the atom's color choices will shift depending on the strength of the field. Such interactions can be used as the foundation of a device, called an "atomic magnetometer," that can measure unknown magnetic fields. This investigation studies interactions between laser light and a specially prepared gas of atoms that is sensitive to small variations in the surrounding magnetic field. The special preparation uses two lasers and a controlled magnetic field to temporarily but dramatically change how laser light travels through a gas of atoms. As a result, the laser light's brightness fluctuates, or flickers, in ways that are not yet fully understood. These fluctuations not only carry information about the atoms, but they are also especially sensitive to magnetic field variations. This research will further our scientific understanding of atom-light interactions, which is of broad interest for many technological applications. Simultaneously, the research will produce new techniques for detecting small, unknown magnetic fields, like the magnetic fields emitted from the human heart. The new detection methods will potentially impact a broad range of medical and scientific fields, and because they make use of low-cost and potentially portable laser systems, any resulting technological applications will be widely accessible and suitable for use outside of the laboratory environment. Undergraduate students will be involved at all stages of this research agenda, preparing them for careers in research science and other STEM-related fields. Light intensity fluctuations derived from atomic coherence can encode valuable information about coherence dynamics in an atomic vapor. Furthermore, they provide a platform for a new class of compact and simple atomic magnetometers. This research agenda uses low-cost, free-running diode lasers with inherent frequency noise that is converted into information-rich intensity noise near an atomic resonance. The amplitude and phase of the intensity fluctuations are particularly sensitive to small magnetic field variations near an atomic coherence between Zeeman sublevels. Hanle effect Electromagnetically Induced Transparency will be induced in rubidium vapor and used to prototype and optimize a novel magnetometry technique relying on coherence-derived light fluctuations. The converted laser intensity noise will be studied using self-correlations and spectrum analysis. The findings will deepen our understanding of the relationship between the light fluctuations and the underlying atomic coherence, as well as give us the tools to build a new atomic magnetometer. Moreover, the results will provide useful insight for mitigating noise from imperfect lasers.

21世纪物理学的重大进步依赖于发现原子的性质不是固定的，而是可以通过与激光的相互作用而改变的。理解和控制这些敏感的相互作用的能力也是创造新的基于原子光的技术的关键。一些原子与光的相互作用对周围的磁场很敏感。举个例子，一个原子对它吸收的光的精确颜色是非常有选择性的，但是当它被置于磁场中时，原子的颜色选择将根据磁场的强度而改变。这种相互作用可以作为一种叫做“原子磁强计”的设备的基础，它可以测量未知的磁场。这项研究研究了激光与一种特殊制备的原子气体之间的相互作用，这种气体对周围磁场的微小变化很敏感。这种特殊的制备方法使用两个激光器和一个可控的磁场来暂时但戏剧性地改变激光在原子气体中的传播方式。因此，激光的亮度波动或闪烁，其方式尚不完全清楚。这些波动不仅携带着原子的信息，而且对磁场的变化也特别敏感。这项研究将进一步加深我们对原子-光相互作用的科学理解，这对许多技术应用具有广泛的兴趣。同时，这项研究将产生探测小的、未知磁场的新技术，比如人类心脏发出的磁场。新的检测方法将潜在地影响广泛的医学和科学领域，并且由于它们使用低成本和潜在的便携式激光系统，因此任何由此产生的技术应用将广泛可获得并适合在实验室环境之外使用。本科生将参与这项研究议程的所有阶段，为他们在研究科学和其他stem相关领域的职业生涯做好准备。由原子相干性产生的光强度波动可以编码有关原子蒸气中相干动力学的有价值的信息。此外，它们还为新型紧凑简单的原子磁力计提供了一个平台。这项研究议程使用低成本、自由运行的二极管激光器，其固有的频率噪声在原子共振附近转化为信息丰富的强度噪声。强度波动的幅度和相位对塞曼亚能级之间原子相干性附近的小磁场变化特别敏感。汉勒效应电磁感应透明将在铷蒸气中产生，并用于基于相干衍生光波动的新型磁强计技术的原型和优化。转换后的激光强度噪声将使用自相关和光谱分析进行研究。这一发现将加深我们对光波动与潜在原子相干性之间关系的理解，并为我们建立新的原子磁强计提供工具。此外，结果将为减轻不完美激光器的噪声提供有用的见解。