Nanolight sources based on resonant excitons of
plasmons near a sharp metallic nanostructure have attracted great
interest in optical nanoimaging. However, the resonant phenomenon
only works for one type of wavelength that resonates with plasmons.
Compared to plasmonic resonance, the alternative plasmon
nanofocusing method can generate a source of nanolight by
propagating and compressing plasmons on a tapered metallic
nanostructure, independent of wavelength, due to its reliance on
propagation. In a new report on Science Advances, Takayuki Umakoshi
and a research team in applied physics and chemistry in Japan
generated a white nanolight source spanning across the entire
visible light range through plasmon nanofocusing. Using the
process, they demonstrated spectral bandgap nanoimaging of carbon
nanotubes (CNTs). The experimental demonstration of the source of
white nanolight will enable diverse research fields to progress
toward next-generation, nanophotonic technologies.

