This technique of improving the accuracy of g⁽²⁾(τ) measurement is useful to extract higher order coherence and achieve desired laser source for quantum imaging and secure communication.

The second order photon correlation g⁽²⁾(τ) of a chaotic optical-feedback semiconductor laser is precisely measured using a Hanbury Brown–Twiss interferometer. The accurate g⁽²⁾(τ) with non-zero delay time is obtained experimentally from the photon pair time interval distribution through a ninth-order self-convolution correction. The experimental results agree well with the theoretical analysis. The relative error of g⁽²⁾(τ) is no more than 5‰ within 50 ns delay time. The bunching effect and coherence time of the chaotic laser are measured via the precise photon correlation technique. This technique provides a new tool to improve the accuracy of g⁽²⁾(τ) measurement and boost applications of quantum statistics and correlation.