Plasmonic Sensors Based on a Metal-Insulator-Metal Waveguide-What Do We Know So Far?

Abstract

Metal-insulator-metal (MIM) waveguide-based plasmonic sensors are significantly important in the domain of advanced sensing technologies due to their exceptional ability to guide and confine light at subwavelength scales. These sensors exploit the unique properties of surface plasmon polaritons (SPPs) that propagate along the metal-insulator interface, facilitating strong field confinement and enhanced light-matter interactions. In this review, several critical aspects of MIM waveguide-based plasmonic sensors are thoroughly examined, including sensor designs, material choices, fabrication methods, and diverse applications. Notably, there exists a substantial gap between the numerical data and the experimental verification of these devices, largely due to the insufficient attention given to the hybrid integration of plasmonic components. This disconnect underscores the need for more focused research on seamless integration techniques. Additionally, innovative light-coupling mechanisms are suggested that could pave the way for the practical realization of these highly promising plasmonic sensors.

Keywords: metal–insulator–metal waveguide; plasmonics; surface plasmon polariton.

Figure 4

Plasmonic devices based on MIM WG for (a) biosensing [67], (b) biosensing [68], (c) biosensing [72] (d) biosensing [21], (e) temperature sensing [133], (f) gas sensing [22], and (g,h) gas sensing [34].

Figure 1

Norm. E-field pattern in the MIM WG for the nanoslot of (a) 100 nm, (b) 75 nm, and (c) 50 nm.

Figure 2

Graphical illustration of the topics discussed in this paper, which include performance parameters, material platforms, numerical methods, sensing devices, and light-coupling mechanisms.

Figure 3

(a) Graphical illustration of the sensor [110], (b) E-field pattern at the resonant wavelength [110], and (c) real and imaginary parts of permittivity of ZrN in the visible and near-IR spectrum [110].

Figure 5

(a) Graphical illustration of a plasmonic sensing device for concurrent detection of biological samples and temperature [149], (b) transmission spectrum of the device showing two independent resonant dips [149], and (c) deviation in the RI of the PDMS material set against the ambient temperature [149].

Figure 6

(a) SEM image of the mode converter [169], (b) CE of the mode converter versus gap width [169], (c) CE of the mode converter versus taper length [169], (d) graphical illustration of MIM WG- based plasmonic sensor integrated with Si tapered WG [155], (e) transmission spectrum of the device in the presence of different RI materials, (f) λ_res versus RIU, and norm. E-field pattern in the device in (g) off-resonance state [155] and (h) on-resonance state [155].

Figure 7

(a) SEM image of the orthogonal coupling configuration [167], (b) graphical depiction of a plasmonic sensor integrated with orthogonal mode couplers [137], (c) norm. E-field pattern in the device in an on-resonance state [137], and (d) norm. E-field pattern in the device in an off-resonance state [137].