In this paper, the simultaneous switching and sensing capabilities of a compact plasmonic structure based on a conventional rectangular hole in a silver film are proposed and investigated. The proposed structure has ultrahigh sensitivity up to 3000 nm/RIU and high figure of merit of 170 RIU⁻¹. Also, the simulation results show the potential of the presented refractive index sensor to detect malaria infection, cancer cells, bacillus bacteria, and solution of glucose in water. Simultaneously, by changing the incident lightwave polarization, the structure behaves like a plasmonic switch, which has high extinction ratios of 15.81, 31.20, and 25.03 dB at three telecommunication wavelengths of 850, 1310, and 1550 nm, respectively. The ultrafast response time of 20 fs is achieved for the wideband application of the switching capability at the wavelength range of 1056 to 1765 nm. Moreover, the equivalent circuit model and transmission (ABCD) matrix methods are derived to validate the simulated results. Simple design, good agreement between the numerical and analytical results, biomedical applications, ultrahigh sensitivity, and ultrafast performance of the proposed structure help this idea to open up paths for design and implementation of other multi-application plasmonic devices in near-infrared region. To the best of our knowledge, the mentioned analytical methods have not been studied former at near-infrared wavelengths. Therefore, the achievements could pave the way for verifying the simulation results of plasmonic nanostructures in future investigations.

中文翻译：

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具有感测能力的等离子开关在近红外区域的等效电路模型和传输矩阵的解析方法

在本文中，提出并研究了基于银膜中传统矩形孔的紧凑型等离激元结构的同时切换和感测能力。所提出的结构具有高达3000 nm / RIU的超高灵敏度和170 RIU ^-1的高品质因数。此外，模拟结果显示了所提出的折射率传感器在检测疟疾感染，癌细胞，芽孢杆菌细菌和水中葡萄糖溶液方面的潜力。同时，通过改变入射光的偏振，该结构的行为类似于等离子体开关，在三个电信波长850、1310和1550 nm处，消光比分别为15.81、31.20和25.03 dB。在带宽为1056至1765 nm的宽带应用中，实现了20 fs的超快响应时间。此外，推导了等效电路模型和传输（ABCD）矩阵方法以验证仿真结果。设计简单，数值和分析结果之间的一致性好，生物医学应用，超高灵敏度，所提出的结构的超快性能以及这一结构的超快性能，为这一构想开辟了在近红外区域设计和实现其他多应用等离子设备的途径。据我们所知，前面提到的分析方法尚未在近红外波长下进行过研究。因此，这些成果可以为今后研究等离子体纳米结构的仿真结果铺平道路。