Extreme Optical Coherence in Cavity-based Atomic and Molecular Physics

该研究计划将研究一种新的激光方法，该方法有望产生具有相干性和波长控制的光，比目前可用的任何系统都要好两个十倍。这个想法是基于超辐射发射，其中具有极窄原子跃迁的原子系综可以进行量子同步。这就像激光器，只是相干性存储在原子中而不是光中。在过去的十年里，利用超窄光跃迁的原子钟的发展取得了显著的进展。这些系统现在达到了精度和准确度的门槛，开辟了许多潜在的未来应用，包括先进的光通信，重力测绘和大地测量，下一代时间和频率标准，以及先进的导航和全球定位。今天最好的原子钟和探测它们的激光器是有史以来质量最高的相干振荡器，其固有频率在光域中，相干时间现在可以超过分钟。未来的挑战是继续这一令人印象深刻的技术发展，并追求广泛的实际应用。II族原子的超窄相互组合线被限制在光学腔中，为基于宏观原子系综的稳态超辐射的革命性技术提供了一个平台。这样的系统有望大大改善原子钟，因为相干时间可能比迄今为止最好的参考腔稳定激光器长几个数量级。将相干性存储在原子而不是光中克服了参考腔稳定激光器对腔长噪声的固有敏感性，否则腔长噪声直接转化为发射光的频率噪声。本研究计划探索这一想法，以有助于量子光学系统的一般理论，并更明确地理解极端坏腔极限下光学激光器的量子理论。与实验的合作是一个关键方面，允许结果直接影响应用程序和设备的开发。具体目标是定量布局的景观桥梁稳态超辐射和激光，从而探索各种潜在的实现。一个主要的挑战将是识别和减轻量子噪声源，对输出场的光谱相干性产生不利影响。

This research program will study a new approach to lasers that promises to produce light with coherence and wavelength control that is two factors of ten better than any system available today. The idea is based on superradiant emission, where an ensemble of atoms with an extremely narrow atomic transition can undergo quantum synchronization. This is like a laser except the coherence is stored in the atoms rather than the light. The past decade has seen remarkable progress in the development of atomic clocks that utilize ultranarrow optical transitions. These systems are now reaching precision and accuracy thresholds that open up many potential future applications, including advanced optical communications, gravitational mapping and geodesy, next-generation time and frequency standards, and advanced navigation and global positioning. The best atomic clocks today and the lasers that probe them are the highest quality coherent oscillators that have ever existed, with intrinsic frequencies in the optical domain and coherence times that can now exceed minutes. The challenge going forward is to continue this impressive technology development and pursue the broad spectrum of practical applications.The ultranarrow intercombination lines of group-II-like atoms confined in optical cavities provide a platform for a revolutionary technology based on the steady-state superradiance from macroscopic atomic ensembles. Such systems promise to dramatically improve atomic clocks since the coherence time could be orders of magnitude longer than the best reference-cavity stabilized lasers achieved to date. Storing the coherence in the atoms rather than the light overcomes the intrinsic sensitivity of reference-cavity stabilized lasers to cavity length noise, which otherwise translates directly into frequency noise on the emitted light.This research program explores this idea to contribute to the general theory of quantum optics systems and more explicitly to the understanding of the quantum theory of the optical laser in the extreme bad-cavity limit. Collaboration with experiment is a key aspect allowing the results to impact directly in the development of applications and devices. The specific goal is to quantitatively layout the landscape that bridges steady-state superradiance and lasing and to thereby explore the variety of potential implementations. A major challenge will be to identify and mitigate quantum noise sources that adversely affect the spectral coherence of the output field.