Fotonisen

Fotonisen is a term used in certain discussions of photonics to describe a hypothetical or emergent photonic excitation that arises from strong coupling between light and matter in nanoscale structures. In this usage, a fotonisen is a localized, quasi-particle‑like state that carries light energy through a medium with properties distinct from a bare photon, such as modified dispersion, enhanced nonlinearity, or reduced diffraction. It is analogous to, but not identical with, polaritons or solitons, and in some accounts it emphasizes the photonic component over the matter component.

Origin and usage: The word combines "photon" with a suffix suggesting a state or particle. The concept has appeared in a small number of theoretical and experimental studies since the 2010s, but there is no universal definition, and the term is not widely standardized.

Realizations: The fotonisen concept is associated with systems where strong light–matter coupling is engineered, such as semiconductor microcavities, metasurfaces with resonant nonlinearities, and photonic crystals with embedded excitonic or plasmonic resonances. Realizations emphasize coherent propagation, compatibility with integrated photonics, and the ability to tailor dispersion via structure.

Properties and dynamics: In idealized models, fotonisens show a balance between diffraction and nonlinearity, enabling localized propagation. They may exhibit coherence, tunable group velocity, and interaction with other excitations, enabling potential control of light on sub-wavelength scales.

Applications and outlook: If demonstrated robustly, fotonisens could enable compact optical routers, ultrafast switches, or components for quantum photonics. However, due to overlapping terminology, some researchers prefer to describe the phenomena under existing terms such as polaritons or solitons.

See also: polariton, soliton, plasmon, exciton-polariton.