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.

中文翻译：

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在相干频率界面中净化量子点光


量子网络通常在电信波长下运行，以利用光纤中的低损耗传输。然而，发射高度难以区分的光量子态的明亮量子点 （QD），例如 InGaAs QD，通常会发射近红外光子，因此需要对电信频段进行频率转换 （FC）。此外，量子发射的信号质量对于这些网络的有效性能至关重要。在这项工作中，我们报道了一种在周期性极化铌酸锂波导中同时实现单光子从 QD 源到 c 波段的光谱纯化和频移的方法。我们考虑在反向传播配置中产生差分频率，以实现以 GHz 为单位的输出发射带宽的 FC。我们的方法为在混合量子网络中集成高性能单发射极源建立了一条清晰的道路。