  Revealing hidden non-radiative (dark) of resonant nanostructures using
optical methods such as dark-field spectroscopy often becomes a sophisticated
problem due to a weak coupling of these modes with a far-field radiation,
whereas methods of dark-modes spectroscopy, e.g. cathodoluminescence or elastic
energy losses, are not always convenient in use. Here, we suggest an approach
for experimental determining the mode structure of a nanoresonator basing on
utilizing intrinsic incoherent Raman scattering. We theoretically predict the
efficiency of this approach and realize it experimentally for silicon
nanoparticle resonators possessing strong Raman line at 520 cm^-1. With this
method, we studied a silicon nanoparticle placed on a gold substrate and reveal
the spectral position of a low-radiative magnetic quadrupole mode which is
hardly observable with common dark-field optical spectroscopy.
