标题： 气体填充空芯PCF中超快脉冲泵浦调制不稳定的频率关联性塑造 显示英文标题

标题： Shaping frequency correlations of ultrafast pulse-pumped modulational instability in gas-filled hollow-core PCF

摘要： 我们通过调节压力、泵浦脉冲的色散、光纤长度和参量增益，改变由超快脉冲泵浦调制不稳定性（MI）双光束在充满氩气的空芯kagomé结构光子晶体光纤中的时频模式结构。 与实芯系统相比，依赖于压力的色散特性为频率关联的调整提供了更大的灵活性，并且我们证明了泵浦脉冲的色散可以用来调节飞秒泵浦源的联合光谱。 我们还通过对多模二阶关联函数g(2)的测量以及直接重构时频施密特（TFS）模式的形状和权重来表征由此产生的模式内容。 我们表明，模式的数量直接影响调制不稳定性中单次脉冲能量和光谱形状的波动。 使用这种方法，我们仅通过一根光纤就可控制和监测从1.3到4范围内的TFS模式数量。 显示英文摘要

摘要： We vary the time-frequency mode structure of ultrafast pulse-pumped modulational instability (MI) twin beams in an argon-filled hollow-core kagom\'e-style PCF by adjusting the pressure, pump pulse chirp, fiber length and parametric gain. Compared to solid-core systems, the pressure dependent dispersion landscape brings increased flexibility to the tailoring of frequency correlations and we demonstrate that the pump pulse chirp can be used to tune the joint spectrum of femtosecond-pumped sources. We also characterize the resulting mode content, not only by measuring the multimode second-order correlation function g(2) but also by directly reconstructing the shapes and weights of time-frequency Schmidt (TFS) modes. We show that the number of modes directly influences the shot-to-shot pulse-energy and spectral-shape fluctuations in MI. Using this approach we control and monitor the number of TFS modes within the range from 1.3 to 4 using only a single fiber.