Microwave‐to‐Optical Conversion and Amplification in Cavity Optomagnonics System

Abstract A scheme to construct microwave‐to‐optical conversion and amplification using a hybrid cavity optomagnonics system is presented. A yttrium iron garnet (YIG) sphere with nonlinearity couples to optical transverse‐electric (TE) and transverse‐magnetic (TM) whispering gallery modes and a microwave mode. It is shown that the TM classical mode can control the quantum signals input from the microwave mode transmission into the optical TE mode. Due to the nonlinearity of the YIG sphere as well as effective magnon‐optical nondegenerate parametric amplification form interaction, the microwave quantum signals can be amplified and transmitted into the optical TE mode. The current system can function well as a quantum transistor, which is important for constructing a quantum circuit using a cavity optomagnonics system.