Abstract The paper is devoted to optical testing of mid-infrared Ge/Si photodetectors obtained by stacking of self-assembled Ge quantum dots in multilayer structures, which are near-field coupled to the adjacent nanoplasmonic arrays of subwavelength holes in metallic films. It is shown that photocurrent and near-field spectra consist of several sets of peaks, which are attributted to surface plasmon waves, localized surface plasmon modes or diffractive Rayleigh anomaly depending on the hole diameter and the angle of incidence θ. We find that for small holes the greatest contribution to the photocurrent enhancement is due to the excitation of the surface plasmon-polariton waves for all θ. As the hole diameter is increased and becomes comparable with the array periodicity, the normal-incident photoresponse improvement is provided by the Rayleigh anomaly. With the increase of incident angle, the photocurrent enhancement is supposed to arise from coupling of the localized shape resonance and propagating plasmon modes.

中文翻译：

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量子点光电探测器中的中红外光学共振与不同孔径直径的金属光栅耦合

摘要 本文致力于通过在多层结构中堆叠自组装 Ge 量子点获得的中红外 Ge/Si 光电探测器的光学测试，这些量子点与金属薄膜中的亚波长孔的相邻纳米等离子体阵列近场耦合。结果表明，光电流和近场光谱由几组峰值组成，这些峰值归因于表面等离子体波、局部表面等离子体模式或衍射瑞利异常，具体取决于孔径和入射角 θ。我们发现，对于小孔，对光电流增强的最大贡献是由于所有 θ 的表面等离子体 - 极化波的激发。随着孔径的增加，变得与阵列周期性相当，正常入射光响应改进由瑞利异常提供。随着入射角的增加，光电流增强应该是由局域形状共振和传播等离子体模式的耦合引起的。