Figure 3

Second-order correlation function (g⁽²⁾(τ)) of down-conversion photons. (a) Self-correlation measurement of degenerate down-conversion photon pairs. Right inset: Power dependence of degenerate photon-pair generation rate. Normalized generation rate of 3.0 MHz mW⁻¹ has been fitted. (b) Cross-correlation measurement of the nearest non-degenerate down-conversion photon pairs. (c) Self-correlation measurement of the idler in the nearest non-degenerate down conversion. The left insets in a–c show the schematics of each measurement. The solid lines are fittings with the convolution function between a double exponential decay and a Gaussian distribution function related to the chosen bin width and detector jitter.