This work demonstrates a novel strategy to improve the sensing performance of a prism-coupled surface plasmon resonance system by Gaussian beam shaping and multivariate data analysis. The propagation of the beam along the optical system has been studied using the Gaussian beam approximation to design the incident beam such that the beam waist is aligned precisely and that stability is assured at the metal–dielectric interface. This renders a collimated incident beam, hence least angular dispersion, yielding a stronger and sharper plasmonic resonance. Moreover, we use the multivariate analysis method partial least squares that combines multiple features of the surface plasmon resonance curve and allows for a more precise analysis of the plasmonic response. Compared to univariate analysis, partial least squares improves typical sensing performance parameters remarkably. The combination of both aspects, beam shaping and multivariate analysis, overcomes current limitations of plasmonic detection systems. Thereby, we improve analytical sensitivity by a factor of 16, decrease the prediction error of the concentration of an unknown analyte by a factor of 11, and enhance resolution to the order of 5 × 10^–7 RIU in angular interrogation.

中文翻译：

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等离子体感测中的高斯光束整形和多元分析

这项工作展示了一种通过高斯光束整形和多元数据分析来改善棱镜耦合表面等离子体激元共振系统的传感性能的新策略。已经使用高斯光束近似法研究了光束沿光学系统的传播，以设计入射光束，从而使光束腰部精确对准，并确保了金属-电介质界面的稳定性。这将产生准直的入射光束，从而产生最小的角度色散，从而产生更强，更清晰的等离子体共振。此外，我们使用了多元分析方法的偏最小二乘法，该方法结合了表面等离振子共振曲线的多个特征，并允许对等离激元响应进行更精确的分析。与单变量分析相比，偏最小二乘可显着改善典型的传感性能参数。波束成形和多元分析这两个方面的结合克服了等离子体检测系统的当前限制。因此，我们将分析灵敏度提高了16倍，将未知分析物浓度的预测误差降低了11倍，并将分辨率提高了5×10数量级。^–7 RIU在角度询问中。