A gigahertz surface magneto-plasmon optical modulator

We propose a novel high-speed magnetooptic (MO) modulator based on the optical excitation of surface magneto-plasmon (SMP) waves in bismuth-substituted yttrium iron garnet (Bi-YIG). A model describing magnetization dynamics of the Bi-YIG film is used in conjunction with an SMP reflectivity model to evaluate the performance of the device. In developing the reflectivity model, the dispersion relation for the SMP waves at a Bi-YIG-metal interface is derived. The optical response of the device is modeled for various driving pulses, and the performance of the device is discussed in terms of response time, efficiency, and bandwidth. Using practical material parameters, it is found that the modulator has an improved efficiency over MO modulation devices relying on bulk propagation for comparable driving current pulse durations, as well as the added benefits of a miniature design, multigigahertz operation, and tunable bandwidth. The analysis presented here provides a useful framework for the design and development of magneto-plasmon photonic devices.