Effective second-order correlation function and single-photon detection

Peter Grünwald
2019 New Journal of Physics  
Quantum-optical research on semiconductor single-photon sources puts special emphasis on the measurement of the second-order correlation function g (2) (τ), arguing that g (2) (0)<1/2 implies the source field represents a good single-photon light source. We analyze the gain of information from g (2) (0) with respect to single photons. Any quantum state, for which the second-order correlation function falls below 1/2, has a nonzero projection on the single-photon Fock state. The amplitude p of
more » ... The amplitude p of this projection is arbitrary, independent of g (2) (0). However, one can extract a lower bound on the single-to-multi-photon-projection ratio. A vacuum contribution in the quantum state of light artificially increases the value of g (2) (0), cloaking actual single-photon projection. Thus, we propose an effective second-order correlation function˜( ) ( ) g 0 2 OPEN ACCESS RECEIVED
doi:10.1088/1367-2630/ab3ae0 fatcat:l7mqwnfr2rd7jcmsabuzhxlcne