光分插复用器是集成光学的重要单元器件之一。针对光分插复用器在十字交叉处存在损耗问题, 研究了交叉耦合系数对信道波导与微环间距和各信道输出光谱的影响。用耦合模理论推导了各信道输出光谱的解析表达式, 并对光谱图进行分析。研究发现, 信道波导与微环间距为66.16 nm时, 交叉耦合系数最小, 交叉耦合系数的存在使谱线呈法诺共振曲线。由对数值解和仿真解的比较, 得出仿真解与数值解吻合得很好。

Optical add-drop multiplexer is one of the promising components for integrated optics. For the existence of loss at the cross of optical add-drop multiplexer, the influence of the insertion loss on the gap between channel and microring over the output spectrum is introduced. Based on mode coupling theory, the analytical expressions are derived. The output spectra are simulated and compared. The simulation results show that the cross coupling coefficient is the smallest when the gap is 66.16 nm. The spectrum exhibits an asymmetric Fano-resonance line shape because of the existence of the cross coupling. The finite difference time domain (FDTD) simulation results agree well with the analytical results from the comparison between FDTD and analytical results.