标题： 在现成非线性光学波导中实现时间模式选择性频率转换：从理论到实验 显示英文标题

标题： Engineering temporal-mode-selective frequency conversion in off-the-shelf nonlinear optical waveguides: From theory to experiment

摘要： 量子频率转换（QFC）在非线性光学介质中是一种强大的工具，用于时间模式的选择性操控光。 最近尝试实现高模式选择性和/或保真度时，不得不采用多维优化方案来确定系统的自然 Schmidt 模式。 某些相关频段之间的相对群速度、介质长度和时间脉冲宽度的组合已被证明可以实现良好的选择性（超过 80%），对于与泵浦脉冲形状几乎相同的时域模式，即使在高转换效率下也是如此。 在这一参数范围内，使用现成的二次谐波生成 MgO:PPLN 波导，并在约 800 nm 波长处使用 500 fs 左右的脉冲，我们实验验证了模型预测的 Schmidt 模式确实提供了预期的高时间模式选择性。 这为实施一种预测可达到近完美（100%）选择性的两阶段 QFC 方案铺平了道路。 显示英文摘要

摘要： Quantum frequency conversion (QFC) in nonlinear optical media is a powerful tool for temporal-mode selective manipulation of light. Recent attempts at achieving high mode selectivities and/or fidelities have had to resort to multi-dimensional optimization schemes to determine the system's natural Schmidt modes. Certain combinations of relative-group velocities between the relevant frequency bands, medium length, and temporal pulse widths have been known to achieve good selectivities (exceeding 80%) for temporal modes that are nearly identical to pump pulse shapes, even for high conversion efficiencies. Working in this parameter regime using an off-the-shelf, second-harmonic generation, MgO:PPLN waveguide, and with pulses on the order of 500 fs at wavelengths around 800 nm, we verify experimentally that model-predicted Schmidt modes provide the high temporal-mode selectivity expected. This paves the way to the implementation of a proposed two-stage QFC scheme that is predicted to reach near-perfect (100%) selectivity.