  Optical nanofibres are used to confine light to subwavelength regions and are
very promising tools for the development of optical fibre-based quantum
networks using cold, neutral atoms. To date, experimental studies on atoms near
nanofibres have focussed on fundamental fibre mode interactions. In this work,
we demonstrate the integration of a few-mode optical nanofibre into a
magneto-optical trap for $^{87}$Rb atoms. The nanofibre, with a waist diameter
of $\sim$700 nm, supports both the fundamental and first group of higher order
modes and is used for atomic fluorescence and absorption studies. In general,
light propagating in higher order fibre modes has a greater evanescent field
extension around the waist in comparison with the fundamental mode. By
exploiting this behaviour, we demonstrate that the detected signal of
fluorescent photons emitted from a cloud of cold atoms centred at the nanofibre
waist is larger ($\sim$6 times) when higher order guided modes are considered
as compared to the fundamental mode. Absorption of on-resonance, higher order
mode probe light by the laser-cooled atoms is also observed. These advances
should facilitate the realisation of atom trapping schemes based on higher
order mode interference.
