Metal‐insulator‐metal waveguide‐based plasmonic sensors: Fantasy or truth—A critical review

Abstract

There is a hysteria over plasmonic sensors based on metal‐insulator‐metal (MIM) waveguides and researchers around the globe are extensively studying these devices over the past two decades for diverse sensing applications for instance temperature, refractive index, pressure, and biochemical applications among others. The sensors based on MIM waveguides (WGs) are compact and offer unmatchable sensitivity as assessed with dielectric waveguide‐based sensors along with an extraordinary figure of merits (FOM). However, the major concern is that most of these sensors are only numerically simulated/analyzed and there is no experimental demonstration accessible to date. Therefore, in this mini‐review, these highly alluring sensor designs are critically analyzed to identify if they are practically feasible or just a fantasy among the scientific community.

A Review of Photonic Sensors Based on Ring Resonator Structures: Three Widely Used Platforms and Implications of Sensing Applications

“…Due to their capacity to surpass the diffraction limit of light, SPP WG structures, specifically MIM WGs, have received considerable consideration [ 123 ]. Due to their small size, ease of integration, and favorable balance between light localization and transmission loss, MIM WGs are expected to enable the realization of highly integrated optical circuits [ 124 , 125 ].…”

Miniaturized Design of a 1 × 2 Plasmonic Demultiplexer Based on Metal–Insulator-Metal Waveguide for Telecommunication Wavelengths

“…The MIM plasmonic waveguide devices have been thoroughly researched for several intriguing applications [11]. The coupling of the incident light to the nanosized MIM plasmonic waveguide, however, has not received any attention [29]. Since light can be dispersed at the interface, it is impossible to effectively couple light from the fiber to the metallic waveguide.…”

“…Moreover, there are several other interesting works on plasmonic demultiplexers [25][26][27][28]; however, all of them failed to provide a mechanism for lighting coupling to the MIM waveguide. This is the reason, there is no experimental demonstration of the plasmonic device based on a MIM waveguide is yet available [29].…”

Metal‐Insulator‐Metal Waveguide Plasmonic Sensor System for Refractive Index Sensing Applications

“…[2,9,14] However, this matter has been extensively discussed in our previous review paper. [46] To transform a signal that is moving in a dielectric WG into a plasmonic signal that can be relayed through a plasmonic WG, components known as dielectric-to-plasmonic mode converters are used. Dielectric and plasmonic WGs can be integrated into nanophotonic circuitry with the help of this kind of conversion.…”