ABSTRACT
This chapter discusses various types of resonances and the sensors designed using these resonances. It discusses the new optical technique of lossy mode resonance and its development for sensing purposes. Spectral interrogation is another widely used interrogation scheme for the realization of surface plasmon resonance (SPR)-based sensors. The unpolarized light has both transverse electric (TE) and transverse magnetic (TM) modes, and SPR is achieved only by TM modes and TE modes do not make any effects on surface plasmons. The chapter shows the long-range SP mode in a dielectric–metal–dielectric configuration. An unclad core region on the optical fiber has a coating of a plasmonic metal of suitable thickness. Magneto-optic SPR is a plasmonic resonance phenomenon realized by combining SPR and magneto-optic Kerr effect. In a dual-mode sensor, sensitivity enhancement can be achieved by creating the cavities or periodic gaps in the metal layer.
