Photonic crystal resonators with the C_4v symmetry were designed and fabricated on quantum cascade lasers with a strain-compensated multiple quantum well to achieve single-mode and vertical surface emission at 4.32 μm. Their fabrication accuracy was confirmed by high-resolution reflection spectroscopy. The maximum output power was 10 mW at 77 K. A far-field pattern with a small divergence angle below 1 degree was observed. Its main peak had a donut shape, which was attributed to the spatial symmetry of the resonance mode of the photonic crystal.

中文翻译：

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用于工作在 4.32 μm 的应变补偿量子级联激光器的单模和垂直表面发射的光子晶体谐振器的设计和制造

_{在具有应变补偿多量子阱的量子级联激光器上设计并制造了具有 C 4v}对称性的光子晶体谐振器，以实现 4.32 μ m的单模和垂直表面发射。高分辨率反射光谱证实了它们的制造精度。在 77 K 时最大输出功率为 10 mW。观察到具有小于 1 度的小发散角的远场图案。其主峰呈环形，这归因于光子晶体共振模式的空间对称性。