Surface plasmon resonant devices and methods of use thereof

A resonant plasmonic device for guiding and localizing electromagnetic radiation, the resonant plasmonic device comprising:

• a support structure comprising a plurality of unit plasmonic resonators;
• each unit plasmonic resonator comprising adjacent conductive surfaces having a dielectric region formed therebetween, thereby defining a resonant cavity;
• wherein neighbouring unit plasmonic resonators are configured to support the coupling of electromagnetic energy therebetween;
• and
• wherein a spatial gradient in the effective mode index of the unit plasmonic resonators exists among at least a subset of said plurality of unit plasmonic resonators.

A resonant plasmonic device for guiding and localizing electromagnetic radiation, the resonant plasmonic device comprising:

• a support structure comprising a plurality of unit plasmonic resonators;
• each unit plasmonic resonator comprising adjacent conductive surfaces having a dielectric region formed therebetween, thereby defining a resonant cavity;
• wherein a minimum distance between said adjacent conductive surfaces of at least some of said unit plasmonic resonators is less than 100 nm, such that intra-resonator coupling occurs between surface plasmons excited within said adjacent conductive surfaces;
• and
• wherein neighbouring unit plasmonic resonators are configured to support the coupling of electromagnetic energy therebetween;
• and
• wherein a spatial gradient in one or more properties of the unit plasmonic resonators exists among at least a subset of said plurality of unit plasmonic resonators.

A resonant plasmonic device for guiding and localizing electromagnetic radiation, the resonant plasmonic device comprising:

• a support structure comprising a plurality of unit plasmonic resonators;
• each unit plasmonic resonator comprising adjacent conductive surfaces defining an intra-resonator width, the adjacent conductive surfaces having a dielectric region formed therebetween, thereby defining a resonant cavity;
• wherein the width of at least some of said unit plasmonic resonators is configured such that intra-resonator coupling occurs between surface plasmons excited within said adjacent conductive surfaces;
• and
• wherein neighbouring unit plasmonic resonators are configured to support the coupling of electromagnetic energy therebetween;
• and
• wherein a spatial gradient in the width of the unit plasmonic resonators exists among at least a subset of said plurality of unit plasmonic resonators configured to exhibit intra-resonator coupling.