AI 中文总结
研究发现蒽纳米晶体中单个DBT分子在强连续波驱动下出现反常饱和，提出强度依赖的ESA到短寿命暗态的模型解释该现象，还指出基质质量与脉冲激发方案的相关作用。
AI 中文摘要
固态单有机分子（如有机基质中的二苯并苝（DBT））是重要的确定性单光子源，通常被建模为有效二能级系统（TLS）。我们发现，蒽纳米晶体中的单个DBT分子在强连续波驱动下偏离了该模型：在高共振泵浦功率下，荧光未出现预期的饱和，反而被强烈抑制，且线宽展宽超出TLS预测，形成“反常饱和” regime。通过对比相干与非相干激发、利用声子诱导退相独立校准温度，排除了激光诱导加热与系间窜越的可能。取而代之，依赖强度的激发态吸收（ESA）到短寿命暗态的模型可定量重现荧光抑制与线宽展宽。我们进一步表明，基质质量可缓解这种猝灭，脉冲激发方案对实现完全粒子数反转具有战略意义，对量子纳米光子学与分子光力学有直接影响。
英文摘要
Solid-state single organic molecules, such as dibenzoterrylene (DBT) in organic matrices, are prominent deterministic single-photon sources, usually modeled as effective two-level systems (TLS). We show that single DBT molecules in anthracene nanocrystals, under strong continuous-wave driving, depart from this picture: instead of the expected saturation, fluorescence is strongly suppressed at high resonant pump power, while the linewidth broadens beyond the TLS prediction -- an \emph{anomalous saturation} regime. Comparing coherent and incoherent excitation and independently calibrating temperature via phonon-induced dephasing rules out laser-induced heating and intersystem crossing. Instead, a model of intensity-dependent excited-state absorption (ESA) toward a short-lived dark state quantitatively reproduces both the fluorescence suppression and the linewidth broadening. We further show that matrix quality mitigates this quenching, and that pulsed excitation schemes are strategic toward full population inversion, with direct implications for quantum nanophotonics and molecular optomechanics.
