Strong coupling between free-propagating photons and electronic transition using plasmonics

Interaction of infrared photons with the electronic states of material is widely used in many fields of sensing, such as spectroscopy, thermal imaging, remote sensing, and optical tomography. However, the weak nature of this interaction is the main performance limit in many applications. For example, highly accurate single-molecule sensing could be achieved, if the interaction strength between infrared photons and the molecule could be enhanced. Similarly, we show that enhancing this interaction could lead to infrared detectors with orders of magnitude higher sensitivity (detectivity).