摘要
讨论了麦克斯韦方程在各向同性均匀电介质中的电磁对偶变换不变性 ,定义了电磁混合比 ,求出了对偶场的充要条件 .把上述不变性和充要条件应用于阶跃光纤 ,分析其导波模式 ,证明在非轴对称情况下 ,阶跃光纤中不存在具有色散的受导简正模 .存在的解只有临界折射模 (n =n2 时的特解 ) .求出了它的分立频谱 .受导简正模只存在于轴对称情况中 .以上结论与实验事实不矛盾 。
The adjoint transformation of electromagnetic fields for uniform isotropic dielectric is considered for guided waves in an optical. fiber. The necessary and sufficient condition for two solutions to be a pair of partners is derived. The modes of guided waves are analyzed under this condition. It. is proved that the dispersive normal modes do not exist in the case of non-axial symmetry. the guided modes in such cases are modes of critical refraction, which has a discrete spectrum. The dispersive normal modes ey-ist in axial symmetrical cases. Theoretical predictions are comparable with the experiment data. The behaviour of the fundamental mode shows that it is a mode of critical refraction rather than a dispersive normal mode as is predicted by the theory.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2001年第11期2179-2184,共6页
Acta Physica Sinica
关键词
光纤光学
光波导
电磁对偶变换
导波模式
麦克斯韦方程
fiber optics
electromagnetic wave guides
adjoint transformation of electromagnetic fields
guided waves
