  Quantum networks typically operate in the telecom wavelengths to take
advantage of low-loss transmission in optical fibres. However, bright quantum
dots (QDs) emitting highly indistinguishable quantum states of light, such as
InGaAs QDs, often emit photons in the near infrared thus necessitating
frequency conversion (FC) to the telecom band. Furthermore, the signal quality
of quantum emissions is crucial for the effective performance of these
networks. In this work we report a method for simultaneously implementing
spectral purification and frequency shifting of single photons from QD sources
to the C-band in a periodically poled Lithium Niobate waveguide. We consider
difference frequency generation in the counter-propagating configuration to
implement FC with the output emission bandwidth in units of GHz. Our approach
establishes a clear path to integrating high-performance single-emitter sources
in a hybrid quantum network.
