外加偏置磁场对静磁波模式及其频带的影响

Dependence of Magnetostatic Wave Modes and Bandwidth on Extemal Bias Magnetic Fields

本文完整地展现了磁光薄膜中任意倾斜的外加直流偏置磁场对微波静磁波激发模式及其带宽的影响,实现了对不同静磁模的统一考虑,为进一步分析磁光Bragg器件的衍射性能提供理论基础.计算分析表明:(1)当外加偏置磁场的大小不变时,传统磁化情形下的静磁波带宽最大,此时基于静磁反向体波(MSBVW)的磁光Bragg器件较相应的静磁正向体波(MSFVW)器件有更高的工作频率;(2)在适当倾斜的偏置磁场作用下,MSBVW、MSFVW和静磁表面波(MSSW)均可被激发,它们的激发频率依次增大;(3)通过倾斜偏置磁场可使MSFVW的频带向高频移动.

The dependence of magnetostatic wave（MSW）modes and its bandwidth on the extermal DC bias magnetic fields in the magneto-optic film was illustrated.Three kinds of magnetostatic modes,those of the magnetostatic backward volume wave （MSBVW）,the magnetostatic forward volume wave（MSFVW）and the magnetostatic surface wave（MSSW）,were taken into account together by studying the generation of the magnetostatic waves under arbitrarily tilted bias magnetic field,and then the diffraction performance of the MSW-based magneto-optic Bragg cells may easily be calculated.Our calculation shows that,（1）for the same magnitude of external bias magnetic fields,in the conventional magnetization directions there is the largest MSW bandwidth and the operating frequency of the MSBVW-based Bragg cell is higher than that of the MSFVW-based Bragg cell,（2）under an appropriately inclined bias magnetic field,aid three magnetostatic modes can respectively be excited at higher and higher frequencies, and（3）the MSFVW bandwidth may move to higher frequencies by tilting the external bias magnetic field.