Phonon-polaritonics: enabling powerful capabilities for infrared photonics
Devarapu Ganga Chinna, Rao
Subramania Ganapathi, S.
Here, we review the progress and most recent advances in phonon-polaritonics, an emerging and growing field that has brought about a range of powerful possibilities for mid- to far-infrared (IR) light. These extraordinary capabilities are enabled by the resonant coupling between the impinging light and the vibrations of the material lattice, known as phonon-polaritons (PhPs). These PhPs yield a characteristic optical response in certain materials, occurring within an IR spectral window known as the reststrahlen band. In particular, these materials transition in the reststrahlen band from a high-refractive-index behavior, to a near-perfect metal behavior, to a plasmonic behavior – typical of metals at optical frequencies. When anisotropic they may also possess unconventional photonic constitutive properties thought of as possible only with metamaterials. The recent surge in two-dimensional (2D) material research has also enabled PhP responses with atomically-thin materials. Such vast and extraordinary photonic responses can be utilized for a plethora of unusual effects for IR light. Examples include sub-diffraction surface wave guiding, artificial magnetism, exotic photonic dispersions, thermal emission enhancement, perfect absorption and enhanced near-field heat transfer. Finally, we discuss the tremendous potential impact of these IR functionalities for the advancement of IR sources and sensors, as well as for thermal management and THz-diagnostic imaging.
Phonon-polaritons , Superabsorbers , Photonic crystals , Infrared light , Plasmonics , Metamaterials , THz gap
Foteinopoulou, S., Devarapu Ganga Chinna, R., Subramania Ganapathi, S., Krishna, S. and Wasserman, D. 2019. Phonon-polaritonics: enabling powerful capabilities for infrared photonics. Nanophotonics, 8(12), pp. 2129-2175. doi: 10.1515/nanoph-2019-0232