Visualization of an electromagnetic field distribution is helpful for spatial evaluation of field leakage and can aid in solving inverse problems of signal-source estimation. Optical detection is more accurate and less invasive than other methods owing to a low metal content in the sensing probes and signal wires. We have previously reported optical detection of alternating magnetic fields using an alkali-metal atomic magnetometer. In this study, we have proposed a method for imaging the field in a 10 mm diameter area in the sensor head and achieved a resolution below 0.3 mm using a digital micro-mirror device. In this paper, we demonstrate the visualization of an alternating magnetic field at 70 kHz, generated using a Helmholtz coil and a 0.5-mm diameter metal wire attached to the sensor head. Both the uniform field image from the coil and the gradient field image from the wire were clearly observed. The output linearity of the magnetometer was investigated by varying the electric current applied to the coil. In addition, we performed signal-source estimation from the gradient field image. The obtained and calculated distributions were compared to estimate the position of the wire. The estimated wire depth of 1.41 mm was within the range of actual wire depths. This measurement technique has the potential for application in precise position estimation of signal sources with high sensitivity.

中文翻译：

---

使用原子磁强计和数字微镜设备从磁场图像中估计信号源

电磁场分布的可视化有助于场泄漏的空间评估，并有助于解决信号源估计的反问题。由于传感探头和信号线中的金属含量较低，因此与其他方法相比，光学检测更准确，侵入性更小。我们先前曾报道过使用碱金属原子磁力计对交变磁场进行光学检测。在这项研究中，我们提出了一种在传感器头的直径为10 mm的区域中对场成像的方法，并使用数字微镜设备实现了低于0.3 mm的分辨率。在本文中，我们演示了使用亥姆霍兹线圈和连接到传感器头的直径为0.5毫米的金属线产生的70 kHz交变磁场的可视化。清楚地观察到来自线圈的均匀场图像和来自导线的梯度场图像。通过改变施加到线圈上的电流来研究磁力计的输出线性。另外，我们从梯度场图像中进行了信号源估计。比较获得和计算的分布，以估计导线的位置。估计的导线深度为1.41毫米，在实际导线深度的范围内。这种测量技术有潜力以高灵敏度应用于信号源的精确位置估计中。比较获得和计算的分布，以估计导线的位置。估计的导线深度1.41毫米在实际导线深度范围内。这种测量技术具有潜在的潜力，可用于高灵敏度的信号源的精确位置估计。比较获得和计算的分布，以估计导线的位置。估计的导线深度为1.41毫米，在实际导线深度的范围内。这种测量技术有潜力以高灵敏度应用于信号源的精确位置估计中。