Broadband Purcell enhancement in plasmonic ring cavities
Broadband Purcell enhancement in plasmonic ring cavities
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DOI：
10.1103/physrevb.82.165419
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发表时间：
2010-10
影响因子：
3.7
通讯作者：
E. Vesseur;F. D. de Abajo;A. Polman
中科院分区：
文献类型：
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作者：
E. Vesseur;F. D. de Abajo;A. Polman
我们给出了一种表面等离子体环形腔几何结构的理论研究，由于极小的光学腔模体积，它显示出很强的自发辐射控制。在金属腔体表面制作V型沟槽，在沟槽底部形成表面等离子体激元模式，其受限程度由沟槽深度和宽度决定。用边界元方法确定了由圆形凹槽定义的环形腔中的共振，与基于线性V型凹槽色散的计算结果一致。腔体品质因数对腔体几何形状Q=1 0-5 0相对不敏感，而模式体积对腔体形状的微小差异非常敏感。最小模体积V=0.000 73 0的环具有10 nm宽，100 nm深的凹槽，侧壁笔直，直径为180 nm。根据腔的几何形状，在E=1.0-1.8 eV的能量范围内，珀塞尔因子远大于2000。对于给定的腔结构，在50-100 meV的宽光谱范围内可以观察到Purcell增强，这使得这些腔的应用超越了典型的低温腔量子电动力学实验。
We present a theoretical study of a surface plasmon ring resonator geometry that shows strong spontaneous emission control due to an extremely small optical cavity mode volume. V grooves made in the surface of a metal confine whispering gallery surface plasmon polariton modes at the bottom of the groove, with the confinement determined by groove depth and width. Resonances in ringlike cavities defined by grooves patterned into circular shape, determined using the boundary-element method, are in agreement with calculations based on dispersion for linear V grooves. Cavity quality factors are relatively insensitive to cavity geometry Q =1 0–5 0 while mode volume is very sensitive to small differences in the cavity shape. The smallest mode volume V = 0.000 73 0 is found for a ring with a 10-nm wide, 100-nm deep groove with straight sidewalls and a diameter of 180 nm. Purcell factors well above 2000 are found in the energy range from E = 1.0– 1.8 eV depending on cavity geometry. For a given cavity geometry the Purcell enhancement is observed over a broad spectral range 50–100 meV, enabling application of these cavities beyond the typical lowtemperature cavity quantum electrodynamics experiments.