【摘要】 从Ｍａｘｗｅｌ理论出发，给出最一般的耦合方程，在此基础上，通过一系列近似简化得出光纤光栅耦合模方程。在解耦合模方程的过程中，推导出同方向和正反方向两种情形耦合模式光功率表达式，并进一步阐述了模式之间的光功率沿着光纤方向发生转换。更多还原

【Abstract】 General coupled mode equations are presented through Maxwell theory,then coupled mode equations of fiber gratings are obtained by a number of approximate reductions.Meanwhile,optical power expressions of two forward propagating modes and one forward and one backward propagating mode are deduced by solving the coupled equations.Consequently,the energy exchange between two modes along the fiber is further discussed.更多还原