  The absorption process of an emitter close to a plasmonic antenna is enhanced
due to strong local electromagnetic (EM) fields. The emission process, if
resonant with the plasmonic system, re-radiates to the far-field by coupling
with the antenna due to the availability of plasmonic states. This increases
the local density of states (LDOS), effectively providing more, or alternate,
pathways for emission. Through the mapping of localized emission events from
single molecules close to plasmonic antennas, performed using far-field data,
one gains combined information on both the local EM field strength and the LDOS
available. The localization from these emission-coupled events generally do
not, therefore, report the real position of the molecules, nor the EM
enhancement distribution at the illuminating wavelength. Here we propose the
use of a large Stokes shift fluorescent molecule in order to spectrally
decouple the emission process of the dye from the plasmonic system, leaving
only the absorption strongly in resonance with the enhanced EM field in the
antennas vicinity. We show that the real position of the emitters in this
complex, but interesting, scenario can be found directly. Moreover, we
demonstrate that this technique provides an effective way of exploring either
the EM field or the LDOS with nanometre spatial resolution.
