Plasmon-induced transparency (PIT) is a spotlight technique for environmental monitoring. In this regard, a highly sensitive and tunable multilayer sensor including Ag–SiO₂–Ag is presented in near-infrared range for both transverse mode (TE) and transverse mode (TM) modes at different incident waves. Actually, the proposed multilayer plasmonic sensor is presented to study the optical and sensing properties at near-infrared frequencies based on 3D finite-difference time-domain (FDTD). Sensitivity and tunability of all optical sensors are important parameters in their design, which are calculated based on propagation properties including absorption and reflection spectra, numerically and analytically. Results of absorption and reflection show that the proposed sensor has max sensitivity of 693.8 nm/RIU by Δn = 0.05 changing of middle refractive index and figure of merit (FoM) equal to 9.8. Also, the proposed nano-scale sensor can operate as a light propagation controlling with slow and fast light and multispectral sensor. By using silver metal in the sensor structure, the fast and slow light coefficient is obtained at 220 and 70, respectively. In addition, by increasing the incident angle of light, multiabsorption peaks are created which can be used as multiwindow sensor and PIT. The analytical results are in good agreement with the obtained results of coupled mode theory (CMT) method.

等离子体诱导的透明度（PIT）是用于环境监测的聚光灯技术。在这方面，在不同入射波的横向模式（TE）和横向模式（TM）模式下，都在近红外范围内提供了包括Ag–SiO ₂ –Ag在内的高度灵敏且可调的多层传感器。实际上，提出的多层等离子体传感器是基于3D有限差分时域（FDTD）研究近红外频率下的光学和传感特性。所有光学传感器的灵敏度和可调性是其设计中的重要参数，这些参数是根据包括吸收和反射光谱在内的传播特性进行数值和分析计算得出的。吸收和反射的结果表明，所提出的传感器的最大灵敏度为ΔΔ696.9 nm / RIUn  = 0.05的中间折射率变化和品质因数（FoM）等于9.8。而且，所提出的纳米级传感器可以用作具有慢速和快速光以及多光谱传感器的光传播控制。通过在传感器结构中使用银金属，可以分别在220和70处获得快光系数和慢光系数。另外，通过增加光的入射角，创建了多个吸收峰，可用作多窗口传感器和PIT。分析结果与耦合模理论（CMT）方法的结果吻合良好。