Fig. 2
From: Quantum dot single-photon sources with ultra-low multi-photon probability
Measured degree of second-order coherence. a Example of a measurement for two-photon excitation and filtering on the 2X emission using a pulse length of 3 ps. b Measured values of g(2)[0] as a function of the pulse length for a resonantly driven two-level system (black) and two-photon excitation of 2X (red). Dashed line represents Poissonian statistics of driving laser
