标题： 使用GaAs微腔中的四条准相位匹配产生二次谐波 显示英文标题

标题： Second-harmonic generation using 4-bar quasi-phasematching in a GaAs microdisk cavity

摘要： 材料中的4-bar晶体对称性，如GaAs，可以在无需极化、孪晶或其他工程化畴反转的情况下实现准相位匹配，从而实现高效的频率转换。 4-bar对称性意味着90度的旋转等同于晶体学反演。 因此，在光围绕4-bar轴传播的几何结构中会产生有效的畴反转，这对于准相位匹配是有用的。 微盘光学腔还提供共振场增强和优异的空间重叠，从而在微米尺度体积内实现高效的频率转换。 这些器件可以集成在光子电路中，作为紧凑的辐射源或纠缠光子源。 高效的二阶频率转换是非线性半导体微盘谐振器的新功能，这些器件之前已被用于全光电路作为开关、信号路由器和光学逻辑门进行研究。 微谐振器阵列可以产生慢光和稳健的光学延迟线。 在此，我们首次实验观察到利用4-bar准相位匹配的微盘腔中的高效二次谐波生成。 显示英文摘要

摘要： The 4-bar crystal symmetry in materials such as GaAs can enable quasi-phasematching for efficient frequency conversion without poling, twinning or other engineered domain inversions. 4-bar symmetry means that a 90 degree rotation is equivalent to a crystallographic inversion. Therefore, propagation geometries where light circulates about the 4-bar axis produce effective domain inversions, useful for quasi-phasematching. Microdisk optical cavities also offer resonance field-enhancement and excellent spatial overlap, resulting in highly efficient frequency conversion in micrometer-scale volumes. These devices can be integrated in photonic circuits as compact sources of radiation or entangled photons. Efficient second-order frequency conversion is a new functionality for nonlinear semiconductor microdisk resonators, which have been previously explored for all-optical circuits as switches, signal routers and optical logic gates. Arrays of microresonators can produce slow light and robust optical delay lines. Here, we present the first experimental observation of efficient second-harmonic generation in a microdisk cavity utilizing 4-bar quasi-phasematching.