  Low-noise frequency conversion of single photons is a critical tool in
establishing fibre-based quantum networks. We show that a single photonic
crystal fibre can achieve frequency conversion by Bragg-scattering four-wave
mixing of source photons from an ultra-broad wavelength range by engineering a
symmetric group velocity profile. Furthermore, we discuss how pump tuning can
mitigate realistic discrepancies in device fabrication. This enables a single
highly adaptable frequency conversion interface to link disparate nodes in a
quantum network via the telecoms band.
