Fano resonance is a distinctive spectroscopic behavior in many optical systems. There're certain differences in terms of physics and behavior of Fano resonance compare to dipole resonance which is well recognized. But, what're the specific benefits of Fano resonances over dipole resonances in application point of view or device aspects?
Fano resonance is a misleading term and should in fact be called a Fano interference. You get a Fano interference when you have a broad and narrow resonances interfering with each other, resulting in an asymmetric and sharp spectral peak. This Fano peak is very sensitive to an environmental change and can be used as a detection technique.
In optical systems, on way to obtain a Fano resonance is to place metallic nanoparticles in a lattice (i.e. a plasmonic crystal). See this paper for example Article Coupling Bright and Dark Plasmonic Lattice Resonances
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A typical Fano resonance is obtained when a totally reflecting prism is coupled to a planar waveguide. When the guided wave is not lossy, with an incident gaussian beam, the reflected Fresnel field exhibits a dark line followed by an interference pattern. The light is coupled in the waveguide and after a small path decoupled in the reflected field. Interferences occur between this decoupled field (resonance) and the field directly reflected on the prism base (continuum). The prism coupler is very sensitive to the optical properties of the planar waveguide and can then be used as a sensor.
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