Photon Anti-Bunching and “Hole”-Entanglement with Homodyne Detections

Abstract

Photon anti-bunching, which is characterized by the second-order temporal coherence function g(2)(0) < g(2)(τ), has previously been measured using single-photon counting methods. We experimentally demonstrate a homodyne detection technique for measuring the second-order coherence g(2)(τ) of quantum states of light at sideband frequencies. Our scheme is based on the original Hanbury-Brown-Twiss (HBT) intensity interferometer, but instead replaces all use of photon counters with homodyne detection in each arm (see Fig. 1). The second-order coherence, g(2)(τ), is obtained from a set of quadrature amplitude measurements.