Optical magnetic field sensors based on nanodielectrics: From biomedicine to IoT‐based energy internet

Abstract Smart sensors with excellent performance are accelerating the development of biomedicine and the Internet of Energy. Nanodielectrics exhibit unique electrical and mechanical properties. As the predominant materials in optical magnetic field sensor (MFS), they can not only exert the anti‐interference of optical sensing, but improve the measuring characteristics of optical sensors. For instance, the optical fibre quantum probe for the magnetic field can obtain a higher sensitivity of 0.57 nT/Hz1/2, while the measurement range of the sensor that uses Co‐doped ZnO nanorods as cladding is 17–180 mT. Here, these exciting recent achievements in the realm of optical sensing methods for magnetic field detection are reviewed, with a focus on nanodielectrics, which provide an emerging opportunity to achieve higher sensitivity and a wider measurement range of MFS.