Cylindrical Vector Beams for Alternating Magnetic Field Sensing Based on YIG Crystal

In this work, a cylindrical vector beams-based magnetic field sensor was proposed and demonstrated by using an yttrium iron garnet (YIG) crystal as the magneto-optical medium. The first-order cylindrical vector beam transmitted through a linear polarizer behind the YIG becomes a two-petal patterned light. When its polarization was rotated by the Faraday effect, the double petal pattern rotated accordingly. A slit was then used for filtering the transmitted patterned light, which was detected by a photodiode. The results showed that it could provide adjustable sensitivity up to 0.147%/mT within a range from
$0.680~\mu $
T to 150mT. This work provides a high bandwidth and high sensitivity cylindrical vector beam magnetic field measurement technique which has potential applications in the field of alternating magnetic field measurements.