The Hong-Ou-Mandel (HOM) effect ranks among the most notable quantum interference phenomena, and is central to many applications in quantum technologies. The fundamental effect appears when two independent and indistinguishable photons are superimposed on a beam splitter, which achieves a complete suppression of coincidences between the two output ports. Much less studied, however, is when the fields share coherence (continuous-wave lasers) or mode envelope properties (pulsed lasers). In this case, we expect the existence of two distinct and concurrent HOM interference regimes: the traditional HOM dip on the coherence length time scale, and a structured HOM interference pattern on the pulse length scale. We develop a theoretical framework that describes HOM interference for laser fields having arbitrary temporal waveforms and only partial overlap in time. We observe structured HOM interference from a continuous-wave laser via fast polarization modulation and time-resolved single photon detection fast enough to resolve these structured HOM dips.

中文翻译：

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非常规时间激光模式的Hong-Ou-Mandel干涉。

Hong-Ou-Mandel（HOM）效应是最著名的量子干扰现象之一，对于量子技术中的许多应用至关重要。当两个独立且不可区分的光子叠加在分束器上时，就会出现基本效果，从而完全抑制了两个输出端口之间的重合。然而，当场共享相干（连续波激光器）或模式包络特性（脉冲激光器）时，研究较少。在这种情况下，我们预计将存在两种不同的并发HOM干扰机制：相干长度时间尺度上的传统HOM下降，以及脉冲长度尺度上的结构化HOM干扰模式。我们开发了一种理论框架，该框架描述了具有任意时间波形且时间仅部分重叠的激光场的HOM干扰。我们通过快速偏振调制和时间分辨的单光子检测，观察到来自连续波激光器的结构化HOM干扰，其速度足以解决这些结构化HOM骤降。