Fiber Mirror Facility Upgrade for Quantum Optics and Sensing

量子光学和传感光纤镜设施升级

• 批准号: RTI-2022-00470
• 负责人: Sankey(Childress), Jack
• 金额: $ 6.26万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742956
• 关键词: Fiber; Mirror; Facility; Upgrade; Quantum

Optical cavities vastly enhance light-matter interactions, making them a ubiquitous tool in optics, quantum optics, and sensing. Recently, microscopic "fiber cavities" have emerged, offering significantly higher bandwidth and tighter confinement, thereby boosting these interactions even further. As a result, five of our six core research directions now rely on fiber cavity technology. The requisite fiber mirror substrates are laser-machined in a shared facility at McGill, and, while this system has vaulted our research to the leading edge of several fields, its low tolerances and lack of flexibility now threaten to halt further progress. As such, we request an upgrade that will improve precision, design flexibility, and throughput. Each research area will greatly benefit from this, but two recent breakthroughs in particular present extraordinary opportunities that prompt an immediate upgrade. First, in the field of optomechanics, we have successfully realized a system comprising an ultralow-noise "trampoline" micromechanical sensor within a fiber cavity, whose motion will be dominated by quantum radiation pressure fluctuations over an unprecedented band of frequencies. This quantum-dominated regime heralds the generation of "squeezed" light useful for surpassing the "standard quantum limit" and preparing arbitrary motional quantum states via feedback, enabling fundamental tests of quantum collapse (e.g. due to gravity), and quantum-enhanced sensors for dark matter searches and force microscopy. However, these exciting opportunities require significantly improved fiber mirrors to efficiently out-couple quantum light: we need precisely positioned, ultrasmooth, and near-flat surfaces that we cannot currently fabricate. Second, in the field of radiation dosimetry, we recently patented a tissue-equivalent in vivo fiber-cavity dosimeter with water as the active medium. Our collaboration with Prof. Enger (MUHC) has now observed promising signals in free space water, verified the radiation hardness of our mirror coatings, and developed techniques and a detailed theory for realizing the optimal dosimeter. We know that the targeted sensitivities require mirrors with much larger radius of curvature than is possible in our existing facility. The proposed upgrade -- which notably utilizes almost all of the existing infrastructure -- addresses all of the above issues, while increasing reliability and throughput. It includes motorized stages for multi-shot ablation of arbitrary profiles on multiple fiber tips and automatic profiling during and after ablation, a fiber cleaver with industry-leading angular tolerances to eliminate detrimental misalignment, and all necessary integration hardware. Beyond this, our facility provides fibers to researchers at Harvard, TU Denmark, Korea University, and Alberta. The infrastructure requested here will increase production, flexibility, and reliability, allowing this community to expand.

光学腔极大地增强了光与物质的相互作用，使其成为光学、量子光学和传感领域普遍存在的工具。最近，微观“光纤腔”的出现，提供了更高的带宽和更严格的限制，从而进一步增强了这些相互作用。因此，我们的六个核心研究方向中有五个现在依赖于光纤腔技术。必要的光纤镜基板是在麦吉尔的共享设施中进行激光加工的，虽然该系统使我们的研究达到了多个领域的前沿，但其低公差和缺乏灵活性现在可能会阻碍进一步的进展。因此，我们请求进行升级以提高精度、设计灵活性和吞吐量。每个研究领域都将从中受益匪浅，但最近的两项突破尤其带来了非凡的机遇，促使其立即升级。首先，在光力学领域，我们成功实现了一个由光纤腔内的超低噪声“蹦床”微机械传感器组成的系统，其运动将由前所未有的频带上的量子辐射压力波动主导。这种量子主导的状态预示着“压缩”光的产生，可用于超越“标准量子极限”并通过反馈准备任意运动量子态，从而实现量子崩溃（例如由于重力）的基本测试，以及量子增强传感器暗物质搜索和力显微镜。然而，这些令人兴奋的机会需要显着改进的光纤镜来有效地耦合量子光：我们需要精确定位、超光滑和近乎平坦的表面，而这是我们目前无法制造的。其次，在辐射剂量测定领域，我们最近获得了一种以水为活性介质的组织等效体内纤维腔剂量计的专利。我们与 Enger 教授 (MUHC) 的合作现已在自由空间水中观察到有希望的信号，验证了我们的镜面涂层的辐射硬度，并开发了实现最佳剂量计的技术和详细理论。我们知道，目标灵敏度需要曲率半径比我们现有设施大得多的镜子。拟议的升级——特别是利用了几乎所有现有基础设施——解决了上述所有问题，同时提高了可靠性和吞吐量。它包括用于对多个光纤尖端上的任意轮廓进行多次烧蚀的电动平台以及烧蚀期间和烧蚀后的自动分析、具有业界领先的角度公差以消除有害的未对准的光纤切割刀以及所有必要的集成硬件。除此之外，我们的工厂还为哈佛大学、丹麦工业大学、高丽大学和阿尔伯塔省的研究人员提供光纤。这里要求的基础设施将提高产量、灵活性和可靠性，从而使该社区能够扩展。