对弱导非均匀折射率分布光纤的严格理论分析表明,显然在纵向场分量的标量波动方程中能够保留▽δ梯度项,但同时在横向场分量的方程中必须略去梯度项.并以TM模为例,给出了梯度项影响的具体表达式;消除了TM与TE模式之间的简并,明确了单模工作条件.

Rigrous analysis for weakly-guiding inhomogeneous refractive index profile optical fiber shows that, while the gradient term can be included in soalrr wave equations of longitudinal field component, it must be neglected in the transverse field equations. Specific expressions of the effect of term on TM modes are obtained, hence bhe degeneracy between TM and TE modes is eliminated and the single-mode condition is clarified.