Optical Magnetic Sensing Using Whispering- Gallery Mode Optomagnonical Cavity

Optical sensors is a hot topic of modern sensing technology with anti-electromagnetic interference, small size and controllable characteristics. In this study, we propose a wide range and mu T resolution magnetometer with the optomagnonics. In the optomagnonical cavity, the existence of opto-magnetic interaction can converse the magnon mode whose frequency is determined by the external magnetic field into an optical mode. We can get this frequency of the magnetic oscillator from the optical mode by optical-microwave synchronous scanning, and then the variation of the external field can be detected. Compared with the previous works that requires additional degrees of freedom, our scheme directly reads out the magnetic field through the optomagnonics which is more stable. Moreover, we present the numerical simulations based on experimental parameters that have been implemented, so our scheme is feasible with current experimental technologies.