Single-photon modulation spectrum

Abstract

We present a robust method of single-photon modulation by directly modulating the single photons and observe its frequency spectrum. Compared with conventional photon counting technique, the single-photon modulation spectrum shows that the method could not only realize high-frequency modulation but also obtain higher signal-to-noise ratio. Moreover, the theoretical calculations show good agreement with the experimental results.

Quantum Coherent Modulation-Enhanced Single-Molecule Imaging Microscopy

“…The signal-to-background (S/B) ratio in the time domain can be represented as where k S represents photons emitted per second from a single molecule and k B represents photons emitted per second from the background. The S/B ratio in the frequency domain can be described as − where t is the integration time (in s) and ξ is the slope factor of modulation, depending on the interaction strength between the single molecule and the pulse pair (for detailed derivation, see the Supporting Information, section 4). Although the S/B ratio does not change in the time domain once the k S and k B are determined, as given in eq , the R S/B (DFT) can be unlimitedly improved in theory by increasing the integration time, as given in eq .…”