The ability to confine light below the diffraction limit — coherently and without loss — has long been considered unattainable in transparent dielectrics. This limitation steered nanophotonics towards plasmonics, in which subwavelength confinement can be achieved at the expense of material absorption. Singular nanophotonics, also called singulonics, is an emerging regime in nanophotonics, which can overcome the trade-off between confinement and loss by leveraging the singular dispersion equation in lossless dielectric media, giving rise to highly localized singular modes, called narwhal wavefunctions. This framework establishes a rigorous, lossless pathway to sub-diffraction confinement, grounded in Maxwell’s equations and governed by the interplay between spatial and momentum uncertainties. This Perspective presents the theoretical foundations and experimental realizations of singular nanophotonics, contrasts it with conventional plasmonic and dielectric approaches and explores its broad implications and challenges.
