Continuously Tunable Frequency Conversion in Germanium Doped Photonic Crystal Fiber Pumped Near Degeneracy

Large-scale quantum networks comprise various components such as photon sources and transmission lines, which operate at diverse wavelengths. The optimal transmission window through solid silica optical fibre is around 1.55 μm while efficient single-photon sources based on InAs quantum dots (QDs) operate in the range of 900–950 nm [1]. High indistinguishability between photons is also required to realise many quantum information technologies but any two dots seldom emit at the same exact wavelength [2] and sending photons through a quantum network may distort their spectra. Parametric nonlinear processes, such as Bragg-Scattering four wave mixing (BS-FWM), enable frequency conversion of photons while preserving their quantum properties [3],[4].