Quantum frequency conversion (QFC) between the visible and telecom is a key to connect quantum memories in fiber-based quantum networks. Current methods for linking such widely separated frequencies, such as sum/difference frequency generation and four-wave mixing Bragg scattering, are prone to broadband noise generated by the pump laser(s). To address this issue, we propose to use third-order sum/difference frequency generation (TSFG/TDFG) for an upconversion/downconversion QFC interface. In this process, two long wavelength pump photons combine their energy and momentum to mediate frequency conversion across the large spectral gap between the visible and telecom bands, which is particularly beneficial from the noise perspective. We show that waveguide-coupled silicon nitride microring resonators can be designed for efficient QFC between 606 and 1550 nm via a 1990 nm pump through TSFG/TDFG. We simulate the device dispersion and coupling, and from the simulated parameters, estimate that the frequency conversion can be efficient (${\gt}80 \%$) at 50 mW pump power. Our results suggest that microresonator TSFG/TDFG is promising for compact, scalable, and low-power QFC across large spectral gaps.

中文翻译：

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通过三阶和差频率生成实现无噪声可见光量子频率转换的提案


可见光和电信之间的量子频率转换（QFC）是连接基于光纤的量子网络中的量子存储器的关键。当前用于链接如此广泛分离的频率的方法，例如和频/差频生成和四波混合布拉格散射，容易受到泵浦激光器产生的宽带噪声的影响。为了解决这个问题，我们建议对上变频/下变频 QFC 接口使用三阶和/差频率生成 (TSFG/TDFG)。在此过程中，两个长波长泵浦光子结合其能量和动量，在可见光和电信波段之间的大光谱间隙中调节频率转换，从噪声角度来看，这特别有益。我们展示了波导耦合氮化硅微环谐振器可以通过 TSFG/TDFG 通过 1990 nm 泵浦设计用于 606 至 1550 nm 之间的高效 QFC。我们模拟器件色散和耦合，并根据模拟参数估计，在 50 mW 泵浦功率下，频率转换可以是高效的 ( ${\gt}80 \%$ )。我们的结果表明，微谐振器 TSFG/TDFG 有望用于跨大光谱间隙的紧凑、可扩展和低功耗 QFC。