複選題

25. Experimental observations show that the fluorescence decay curves of anthracene measured at two different wavelengths do not exhibit simple exponential behavior. Instead, the decay curves display oscillatory features that are $180^{\circ}$ out of phase. Which of the following statements are correct?

(A) Multiple excited states in anthracene are excited non-coherently.
(B) Interference between coherently excited states leads to periodic modulation of the excited-state population, producing oscillations in the fluorescence intensity, a phenomenon known as quantum beating.
(C) In a simple two-level system with incoherent population decay, fluorescence follows a single exponential decay. When coherence is present, the fluorescence intensity contains both exponential decay and oscillatory components, resulting in non-exponential decay behavior.
(D) Fluorescence detected at different wavelengths corresponds to emission from different vibronic transitions. Due to interference, population dynamics between these emitting states can be anticorrelated, leading to oscillations that are $180^{\circ}$ out of phase between the two detection wavelengths.
(E) Fluorescence from the non-coherently excited states leads interference resulting the oscillations in the fluorescence intensity, a phenomenon known as quantum beating.