为提高光子晶体(PC)发光二极管(LED)的光提取效率，引入AlGaN限制层的表面光子晶体LED(PCLED)和嵌入型PCLED两种模型，分析了两种结构中光波模式的分布，利用角分辨测量方法计算光子晶体对LED中各传导模式的提取长度，分析PC对各模式的提取能力，通过研究两种结构中PC的结构参数对提取长度的影响，认为引入AlGaN限制层的LED可以将一部分低阶光波转化为覆盖层模式被PC提取。嵌入型PCLED中，PC与LED中绝大部分传导模式的分布都有重叠，嵌入型PC对所有传导模式都具有较短的提取长度使其能更有效地提高LED的光提取效率。

Two light emitting diode (LED) structures such as the introducing of AlGaN confining layer and the embedded photonic crystal (PC) LED are proposed to improve the light extraction efficiency of PC LEDs. The distributions of guided modes propagated in LED are analyzed, and the modal extraction lengths are calculated using high-resolution angle-resolved measurements in order to research the interaction of each guided mode with PCs. The impact of structure parameters design on modal extraction length is considered. The result shows that the introduction of an AlGaN confining layer in LEDs is effective in extracting a fraction of the optical energy of low order modes, but this approach is limited by the growth of the lattice mismatched AlGaN layer on GaN. And embedded PC LEDs have superior extraction of the guided light due to spatially overlapped with all guide modes which have the higher interaction between all optical modes.