Frequency-resolved photon statistics of resonance fluorescence generated from a two-level system driven by a strong laser field and a weak laser field with equal frequencies are studied. The frequency resolution of fluorescent radiation is described by quantum filtering dynamics, which is simulated theoretically by two single-mode quantum optical cavities with tunable frequencies to scan the incident fluorescent radiation. By calculating the two-photon intensity–intensity correlation functions in terms of the cavity modes, we demonstrate that two-color strong correlations of resonance fluorescence can be generated not only between the opposite sidebands, but also between the central band and one of the sidebands: although both sidebands are broadened due to the perturbation of the weak laser field on the strong-field dressed atom. We emphasize that these properties are in contrast to the conventional case of the standard single-atom Mollow triplet. Moreover, if the resonance frequencies of the two filtering cavities are tuned appropriately, broadband two-color strong correlations are predicted, and the physical origin is revealed from the perspective of quantum interference of photon emission dynamics. This can be considered as a feasible scheme for the design of broadband non-classical light sources, and may be beneficial to the quantum precise detection of atomic and molecular dynamics via quantum optical spectroscopy.

中文翻译：

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两个不同振幅的等频激光场产生的频率分辨单原子共振荧光的宽带强光子相关性

研究了由等频强激光场和弱激光场驱动的两能级系统产生的共振荧光的频率分辨光子统计。荧光辐射的频率分辨率通过量子滤波动力学来描述，其在理论上由两个具有可调频率的单模量子光学腔来扫描入射荧光辐射。通过根据腔模式计算双光子强度-强度相关函数，我们证明了共振荧光的双色强相关性不仅可以在相对的边带之间产生，而且可以在中心带和其中一个边带之间产生：尽管由于弱激光场对强场修饰原子的扰动，两个边带都变宽了。我们强调这些特性与标准单原子 Mollow 三重态的传统情况形成对比。此外，如果适当调整两个滤波腔的共振频率，则可以预测宽带双色强相关性，并从光子发射动力学的量子干涉角度揭示物理起源。这可以被认为是宽带非经典光源设计的可行方案，并可能有利于通过量子光学光谱对原子和分子动力学进行量子精确检测。并从光子发射动力学的量子干涉角度揭示了物理起源。这可以被认为是宽带非经典光源设计的可行方案，并可能有利于通过量子光学光谱对原子和分子动力学进行量子精确检测。并从光子发射动力学的量子干涉角度揭示了物理起源。这可以被认为是宽带非经典光源设计的可行方案，并可能有利于通过量子光学光谱对原子和分子动力学进行量子精确检测。