Ultrafast partial measurement of fourth-order coherence by HBT interferometry of upconversion-based autocorrelation.

We introduce, analyze, and experimentally demonstrate a compact semiconductor-based scheme for a femtosecond-scale partial fourth-order coherence g((4)) measurements. The scheme is based on a start-stop photon-counting Hanbury Brown and Twiss (HBT) interferometry of an upconversion-based Michelson-interferometer autocorrelation. The experimental realization employs second-harmonic generation in a semiconductor quantum-well structure, which may be further integrated with the HBT setup as a miniature photonic circuit, allowing compact characterization devices for photon-pair statistics in quantum photonics and quantum information processing.