Photon Coincidence Simulation Through a Random Splitting of Virtual Photon Timestamps

The single-photon nature and the purity of emitted photons from a light source can be quantified using the second-order correlation function, g
⁽²⁾
(τ). Here, we present simulation results that show how the photon coincidence time window, a characteristic of the utilized photodetection system, affects g
⁽²⁾
(0) for dummy photon timestamps digitally generated at constant emission rates. We use a two-channel virtual interferometer with a beam splitter controlled by a uniform random number selection. We find that g
⁽²⁾
(0) remarkably and quickly squeezes towards the maximum value of a chaotic light photon correlation as the coincidence time window widens. In contrast, tuning the coincidence time window close to the emitter emission decay time yields a coincidence probability of slightly less than one, an antibunching property of light. These simulation findings can participate in improving measurements of quantum light emitters’ coherence functions and revealing the degree of their photon emission purity.