Extraordinary optical transmission has been utilized in many optical applications, but the plasmonic losses hinder their full potential. To obtain enhanced transmission, one of the loss compensation methods is to introduce gain. However, an enhanced transmission or even eliminated absorption does not guarantee plasmonic loss compensation. Here, we reveal the distinction between the transmission enhancement mechanisms in gain-assisted plasmonic arrays. To uncover the underlying mechanisms of the modified transmissions, we calculate the effective electric permittivity by employing a self-consistent gain model. We demonstrate that a large transmission enhancement in a plasmonic system composed of periodic nanocavities and coaxially placed nanoislands, is led by the loss compensation, which manifests itself as narrowing in effective permittivity. In contrast, a slight transmission enhancement in a plasmonic array without the nanoislands arises from the background amplification.

中文翻译：

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杂化等离子体纳米腔中的损耗补偿异常传输

非凡的光传输已经在许多光学应用中得到利用，但是等离激元损耗阻碍了它们的全部潜力。为了获得增强的传输，损耗补偿方法之一是引入增益。然而，增强的透射甚至消除的吸收不能保证等离子体损失的补偿。在这里，我们揭示了增益辅助等离子体阵列中传输增强机制之间的区别。为了揭示修改后的传输的潜在机制，我们通过采用自洽增益模型来计算有效电容率。我们证明，在由周期性纳米腔和同轴放置的纳米岛组成的等离子体系统中，较大的传输增强是由损耗补偿引起的，损耗补偿表现为有效介电常数变窄。