Lee S C, Krishna S, Jiang Y-B, Brueck S R J
Opt Express. 2021 Mar 1;29(5):7145-7157. doi: 10.1364/OE.418686.
A plasmonic-coupled, InAs-based quantum dot photodetector fabricated for mid-wave infrared photonics is reported. The detector is designed to provide a broadband absorption [full width at half maximum (FWHM) ≳ 2 µm] peaked at ∼5.5 µm, corresponding to transitions from the ground state of the quantum dot to the quasi-continuum resonance state above the quantum well. From the coupling of this transition to the surface plasma wave (SPW) excited by an Au film atop the detector, fabricated with a 1.5 µm-period, 2-dimensional array of square holes, a narrowband SPW enhancement peaked at 4.8 µm with an FWHM less than 0.5 µm is achieved. At ∼90 K, a peak responsivity enhanced ∼5× by the plasmonic coupling is observed. Simulation reveals that this enhancement corresponds to collecting ∼6% of the incident light; ∼40% of the total absorption by the SPW excitation at the peak wavelength.
报道了一种为中波红外光子学制造的基于InAs的表面等离子体耦合量子点光电探测器。该探测器旨在提供宽带吸收[半高宽（FWHM）≳2 μm]，峰值波长约为5.5 μm，对应于量子点基态到量子阱上方准连续共振态的跃迁。通过这种跃迁与探测器顶部由1.5 µm周期二维方孔阵列制成的Au膜激发的表面等离子体波（SPW）的耦合，实现了在4.8 μm处峰值的窄带SPW增强，FWHM小于0.5 μm。在约90 K时，观察到表面等离子体耦合使峰值响应率提高了约5倍。模拟结果表明，这种增强对应于收集约6%的入射光；在峰值波长处，约40%的总吸收是由SPW激发引起的。
