EAGER: Ultra-sensitive Atomic Magnetometer based on Fiber-optic Sagnac Interferometer

超灵敏磁力计具有广泛的应用范围，从物理学中的基本对称性测试到地质学中的矿物勘探，再到国家安全中的爆炸物和地雷的检测。特别是，具有毫微微特斯拉（fT或10 E-15 Tesla）磁场灵敏度的磁力计可用于成像脑磁场和研究脑活动（脑磁图或MEG）。利用EAGER赠款，我们将为未来开发基于单光纤的非低温低成本MEG系统以及磁显微镜奠定技术基础，这两种系统都具有超高灵敏度和超快帧速率。这将有助于我们在宏观和微观层面上理解大脑回路。智力优势：无环光纤Sagnac干涉仪是由PI共同开发的，即使在DC下也表现出前所未有的法拉第灵敏度。在这个项目中，这项技术将首次用于提高SERF磁强计对量子极限的灵敏度，超过任何现有的磁强计。由于固有的光纤设计，磁力计的传感器端可以随意定位，并且可以小型化到芯片级，用于观察单个细胞的神经活动。更广泛的影响：该项目将有助于开发新的科学工具来阐明脑回路机制，并将使MEG更便宜，从而更容易用于各种功能性脑疾病的诊断。该项目将为量子物理学、光电子学、生物物理学和科学传播的研究生和本科生提供综合和严格的培训。它还将有助于PI在UCI教授的几门课程的发展。特别鼓励来自代表性不足群体的研究生和本科生参加研究和推广活动

Ultrasensitive magnetometers have a wide range of applications, ranging from tests of fundamentalsymmetries in physics to mineral exploration in geology to the detection of explosives andlandmines in national security. In particular, a magnetometer with femto-Tesla (fT or 10E-15Tesla) magnetic field sensitivity can be used to image brain magnetic fields and study brainactivities (magnetoencephalography or MEG). Using the EAGER Grant, we will develop the technological base for future developments of single fiber based non-cryogenic low cost MEG systems as well as magnetic microscopes, both with ultra-high sensitivity and ultra-fast frame rate. These will help us to understandbrain circuitry at both macroscopic and microscopic levels. Intellectual Merit: The loopless fiber-optic Sagnac interferometer was co- developed by the PI and has demonstrated unprecedented Faraday sensitivity even at DC. In this project, this technique will be used for the first time to improve the sensitivity of SERF magnetometer towards its quantum limit, surpassing any existing magnetometers. As a result of the intrinsic fiber-optic design, the sensor end of the magnetometer can be positioned at will, and can be miniaturized to chip level for observing neural activities of single cells. Broader Impacts: This project will help to develop novel scientific tools for elucidation of brain circuitry mechanism, and will make MEG cheaper thus more accessible for various functional brain disorder diagnosis. The project will provide integrated and rigorous trainings for graduate and undergraduate students of quantum physics, opto-electronics, biophysics and scientific communication. It will also contribute to the development of several courses the PI teaches at UCI. Graduate and undergraduate students from underrepresented groups are especially encouraged to take part in both research and outreach activities