  The integration of cold atomic systems with optical nanofibres is an
increasingly important experimental platform. Here, we report on the spectra
observed during a strongly driven, single-frequency, two-photon excitation of
cold rubidium atoms near an optical nanofibre. At resonance, two competitive
processes, namely a higher excitation rate and stronger pushing of atoms from
the nanofibre due to resonance scattering, need to be considered. We discuss
the processes that lead to the observed two-peak profile in the fluorescence
spectrum as the excitation laser is scanned across the resonance, noting that
the presence of the optical nanofibre dramatically changes the fluorescence
signal. These observations are useful for experiments where high electric field
intensities near an ONF are needed, for example when driving nonlinear
processes.
