A nanoscale sensor which comprises dielectricmetal- dielectric waveguide, and plasmonic metasurface resonators is proposed to realize plasmon-induced transparency responses. The properties of the device are numerically and analytically investigated with different physical parameters. The effect of the incident polarization, geometrical parameters, plasmonic metasurface materials, prism dielectric constant, and the shape of metasurface in near infrared region are then studied to enhance the performance parameters of the structure including the sensitivity, figure-of-merit, and tunability. Our calculations show that the proposed devices are able to operate as a highsensitivity and tunable sensor with maximum figure-of-merit of 480, and sensitivity of 497.8 nm/refractive index unit for slight change of Δn= 0.24, in the refractive index, which stem from its ultra-narrow transparency window and long coupling length between resonators. Furthermore, the structure can be utilized for harnessing light propagation. It is shown that by using silver plasmonic metasurface and appropriate dielectric, a slow up factor as high as 800 is achievable in the proposed structure. We believe that the proposed sensor can be used as a promising platform for future sensing applications such as nanostructure biosensors.

Finding new ways to access the nanoscale and high-$Q$-factor plasmonics resonance remains a major challenge in the field of plasmonic metasurfaces. In the present paper, we aim to report a nanoscale gold metasurface containing structure to realize high-quality plasmon-induced transparency (PIT) responses. The properties of the proposed model are numerically investigated with different physical parameters by the three-dimensional finite difference time domain (3D-FDTD) method. For this purpose, the effects of the geometrical parameters, metasurface materials, dielectric constant, and incident angle in the visible to near-infrared regions are studied. To obtain of dynamical tunability of the proposed model, graphene metasurfaces are then utilized. Numerical results show that the proposed devices are able to operate as high-quality PIT sensors with a maximum figure-of-merit of 1090, and sensitivity of 700 nm/refractive index unit for slight change of $\mathrm{\Delta }n=0.15$, in the refractive index of the dielectric layer, which originates from its ultra-narrow transparency window and strong coupling between dark–bright modes. Moreover, the structure has a nanoscale footprint of $40\mathrm{nm}\times 60\mathrm{nm}\times 31\mathrm{nm}$. We believe that the proposed sensor can be used as a promising platform for future nanosensing applications, such as nanostructure plasmonic sensors.

In the present paper, we aim to report a simple, highly sensitive, and compact footprint biosensor for cancer detection based on metamaterial containing structure utilizing theoretical model. This model includes of array of split ring resonators (SRRs) on a dielectric substrate. The proposed structure is simulated using three-dimensional finite-element method (3D-FEM). To achieve the appropriate operation, the effects of the physical properties including dielectric material, and different cells on the performance of the proposed sensor are considered. For this purpose, three types of dielectrics, including silicon dioxide (SiO2), titanium dioxide (TiO2) and polymethyl methacrylate (PMMA) substrates have been used to evaluate of the biosensor. Calculated sensitivity values for SiO2, TiO2, and PMMA are 658, 653 and 633, respectively, while the figure of merit (FOM) for these three sub-layers are 258, 2431 and 225. According to the simulation results, when the refractive index of a sub-layer is closer to the refractive index of the samples, the sensor is more sensitive. Also, due to the nanometer size of SSRs, it is easy to detect nanometer-sized specimens. The biosensor has a very high resolution so that the capability of measurement and detection of cancer cells is enhanced.

A plethora of research in recent years has been reported on biosensing in the surface plasmon resonant systems. However, very little research has reported a tunable and highly sensitive biosensor in a nanoscale platform. In this regard, we propose a nanoscale hyperbolic metamaterial (HMM)-based prism coupled waveguide sensor (PCWS) in the near-infrared range. The HMM layer makes up one of the constituents of the PCWS—comprised of a periodically arranged assembly of silver nanostrips. The structure is numerically simulated by the finite difference time domain method. It is demonstrated that the sensitivity of the reflected light can be tuned through the refractive index (RI) of the solution. Moreover, the effects of alteration of constituents of PCWS on the sensitivity have been analyzed. Results show that the sensitivity of PCWS can be harnessed by altering the thickness, slant angle of HMM layer, volume fraction ($f$) of metal in the HMM layer, and the incidence angle of light. For this purpose, the structure is numerically simulated by the finite difference time domain method. In the optimum design of the proposed sensor, the maximum value of sensitivity is achieved as high as $S=3450\mathrm{nm}/\text{refractive}$ index unit with $\theta =10°$ and $\varphi =10°$ and a metamaterial thickness of 250 nm. Moreover, the structure has a nanoscale footprint of $600\mathrm{nm}\times 400\mathrm{nm}\times 200\mathrm{nm}$.

Highly tunable enhanced lateral displacements in the center of gravity of a totally reflected light beam from a graphene plasmonic metasurface are investigated. Multiple reflections of the incident beam, and the resonance coupling between the incident beam and the surface modes of the graphene metasurface in each reflection, are employed to enhance the Goos–Hänchen and Imbert–Fedorov shifts in the proposed structure. It is shown that spatial Goos–Hänchen and Imbert–Fedorov shifts as high as $1089{\lambda }_0$ and $-44.66{\lambda }_0$ (${\lambda }_0$: incident wavelength) are achievable in the proposed structure. The effects of different parameters, including the incident beam waist, temperature, the scattering time, and the chemical potential of the graphene, on the shift values are then studied. Because of the strong light confinement in the surface modes of the graphene metasurface, the dispersion properties of these modes, and, therefore, the coupling strength between the incident beam and these modes, are highly sensitive to the parameters of the reflecting structure and the incident beam itself. The high sensitivity of the coupling strength between the incident beam and the surface modes is then exploited to tune the shift values. It is shown that by introducing a small change of $\mathrm{\Delta }{\mu }_C=0.02\mathrm{eV}$ in the chemical potential of the graphene, the spatial Goos–Hänchen and Imbert–Fedorov shift variations of $855{\lambda }_0$ and $-31{\lambda }_0$ can be achieved, respectively. The wide range of lateral shift variations along with the relatively small required actuation power support the application of the proposed structure in the realization of optical devices, such as temperature sensors and switches.