Study On Nonreciprocal Devices Based On Semiconductor Magneto-optical Materials

With the rapid development of optical communication technology,a new generation of optical fiber communication system constantly drives a growing industry demand;miniaturization,function and component is a trend in the development of optical communication devices;magneto-optical waveguide devices based on non-reciprocity has the characteristics of small volume and low cost;small loss,high mechanical stability and other advantage have a very important value nowadays in the development of optical communication industry and optical information processing.In photonic crystals or magnetic surface plasmon composed of magneto-optical materials.the term of magnetic permeability tensor or permittivity tensor of magneto optic material can be changed by external magnetic field,which will destroy the time reversal symmetry or spatial symmetry of the system,so that one-way transmission mode can be research of these functional devices has an important application prospect and research value in optical integration and other fields.In this paper,the dielectric tensor form of magneto optic materials is obtained by solving the Maxwell's equations.The direction of the external magnetic field is different,and the form of dielectric tensor changes.In consideration of the surface plasmon,the dielectric constant of semiconductor material is analyzed briefly according to the Drude model.The dispersion relation of TM mode is deduced through the expansion of Maxwell's equations.A non-reciprocal phase-shifting waveguide optical diode is presented in this paper.Such a device does not need precise phase matching and complex external magnetic field control,and the waveguide optical diode structure is flexible,simple and practical.As the effect the transmission peaks of the forward and reverse transmission,the frequency spacingbetween the transmittance peaks leads to the optical diode function.According needs,the isolation frequency can be adjusted by changing the applied magnetic adjusting the temperature can achieve a good isolation function.At the same time,a compact and highly symmetric three-port circulator with a magneto-optical cavity in a two-dimensional photonic crystal is multiport circulators with port numbers greater than three can be built by cascading the three-port circulator designed can achieve directional transmission in the terahertz band.