3. Surface plasmas in photonic circuits: some application cases

The use of surface plasmons in photonic circuits can greatly enhance certain photonic functions, due to the exaltation of the field and the concentration of optical density at the subwavelength scale. Conversely, the use of waveguides to excite plasmonic structures significantly increases the coupling efficiency of light in these structures. This is all the more remarkable in the case of localized plasmons, which offer the maximum degree of compactness. We present five examples of the use of this type of structure for very different purposes.