利用多層結構聲表面波的精確模型對決定衍射光柵常數的聲表面波傳播特性進行了研究，其衍射光柵可使波導中導模向漏模轉換，這一現象可用耦合模理論解釋。模式轉換效率可化作聲波頻率、聲光作用長度、波導厚度和聲波功率密度的函數，并利用數值計算得出結果。
關 鍵 詞 共線聲光效應; 模式轉換效率; 耦合模理論

Abstract The collinear surface acoustic wave properties that determine the induced grating parameters have been investigated using a rigorous modeling of the surface acouseic wave propagation in multiplayer. The guided-to-leaky mode conversion by the induced diffraction grating from surface acouseic wave is analyzed using a generalized multimode formulation of the coupled mode theory. Mode conversion efficiency has been calculated as functions of acoustic frequency, interaction length, guiding layer thickness, and acoustic drive power density.
Key words collinear acoustooptic interaction; mode conversion efficiency; coupled mode theory