【摘要】 从渐变截面波导与强导近似的阶跃截面波导之间的区别入手 ,推导出了渐变截面MMI区长度的精确表达式 ,并对成像的振幅和相位关系进行了研究。结果表明 ,在相同MMI区宽度条件下 ,渐变截面器件中MMI区最短长度为阶跃截面的两倍 ,但它的设计灵活性却是阶跃截面器件所无法比拟的。更多还原

【Abstract】 Based on the differences between step profile waveguides with s trongly-guided approximation and gradient profile waveguides, the exact express ion of lengths of gradient profile MMI regions is derived, and the amplitudes and phase relationship of the self-images are investigated. The r esult shows that under the condition of same widths of MMI regions, the minimal lengths of gradient profile MMI regions in MMI devices are twice as much as thos e of step profi le regions, but their design flexibility is inaccessible to step profile ones.更多还原