Subwavelength metallic cavities with high-Q resonance modes
Subwavelength metallic cavities with high-Q resonance modes
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DOI：
10.1088/0957-4484/26/8/085201
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发表时间：
2015-02
期刊：
影响因子：
3.5
通讯作者：
N. Ishihara;H. Kurosawa;R. Takemoto;N. A. Jahan;H. Nakajima;H. Kumano;I. Suemune
中科院分区：
文献类型：
--
作者：
N. Ishihara;H. Kurosawa;R. Takemoto;N. A. Jahan;H. Nakajima;H. Kumano;I. Suemune
金属腔在实现小体积纳米腔和纳米激光器方面得到了广泛的研究。然而，由于金属的光学吸收，到目前为止观察到的纳米激光器的腔谐振质量(Q)因子仍然很低(直到∼500)。本文报道了用掺硅∼的亚带隙发射探头在金属腔内观测到低温下最高Q因子为9000，室温下最高Q因子为6000。我们分析了腔模共振波长的温度依赖性，结果表明，折射率项主导了测量的温度依赖性。我们还证明了这种折射率项是与腔模有关的，并且这种拟合过程提供了一种识别腔模的新方法。我们用有限元方法对金属腔进行了模拟，并将高Q腔模归结为回音廊光学模。结果表明，该模式对输出光具有各向同性的偏振依赖性，更适合于量子信息的应用。
Metallic cavities have been extensively studied to realize small-volume nanocavities and nanolasers. However cavity-resonance quality (Q) factors of nanolasers observed up to now remain low (up to ∼500) due to metal optical absorption. In this paper, we report the observation of highest Q factors of 9000 at low temperature and ∼6000 near room temperature in a metallic cavity with a probe of sub-bandgap emission of Si-doped GaAs. We analyze the temperature dependence of cavity-mode resonance wavelengths and show that the refractive-index term dominates the measured temperature dependence. We also show that this refractive-index term is cavity-mode dependent and the fitting procedure offers a new method to identify cavity modes. We simulate the metallic cavity with finite-element method and attribute the high-Q cavity mode to a whispering gallery optical mode. This mode is shown to have isotropic polarization dependence of the output emission, which is preferable for quantum information applications.