Features of the modern development of metal‐insulator‐metal waveguide based plasmonic sensors

Plasmonic sensors based on metal‐insulator‐metal (MIM) waveguides are renowned for their miniaturization and high sensitivity in various sensing applications. A broad spectrum of researchers is numerically investigating the characteristics of MIM waveguide‐based plasmonic sensors with diverse cavity shapes. However, practical demonstrations of these sensors have not yet been realized, primarily due to the overlooked aspect of the light coupling mechanism into these waveguides. In this context, two distinct methods for coupling light into and out of plasmonic chips based on MIM waveguides are presented.