We report the importance of cross-phase modulation (XPM) on the coherence of a low-energy probe pulse co-propagating with a high-energy pump pulse that generates incoherent supercontinuum in all-normal dispersion (ANDi) fiber due to Raman amplification of quantum noise. By investigating numerous fiber and pulse parameters, we show consistently that for weak probe pulses, the XPM from the pump is the dominant influence on the degradation of the probe coherence. We show that the faster decoherence at the pump leading edge means that the probe coherence is reduced more significantly when the probe has a higher group velocity, i.e., when an orthogonally polarized probe is aligned to the fast (lower refractive index) axis of the fiber or when a co-polarized probe has a longer central wavelength. Simulations show that this effect occurs for both polarization-maintaining (PM) and non-PM ANDi fibers and can result in a probe decoherence rate that is higher than that of the pump. These previously unreported results extend our earlier scalar simulations showing incoherent supercontinuum within a single pulse.

中文翻译：

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XPM辅助拉曼放大引起的退相干，用于全正常色散超连续谱生成中的偏振或波长偏移脉冲

我们报告了交叉相位调制（XPM）对低能探针脉冲与高能泵浦脉冲共传播的相干性的重要性，该高能泵浦脉冲由于拉曼放大而在全正常色散（ANDi）光纤中产生了非相干超连续谱。量子噪声。通过研究大量光纤和脉冲参数，我们始终如一地表明，对于弱探针脉冲，来自泵浦的XPM是对探针相干性下降的主要影响。我们表明，在泵浦前沿更快的去相干意味着当探针具有更高的群速度时，即当正交偏振的探针对准光纤的快速（较低折射率）轴时，探针的相干性会大大降低。或当同极化探头的中心波长更长时。仿真表明，这种影响在保偏（PM）和非PMANDi光纤中均会发生，并且可能导致探头的去相干率高于泵的去相干率。这些先前未报告的结果扩展了我们较早的标量模拟，该模拟显示了单个脉冲内的非相干超连续谱。