Quantum phase from photon counting and the Q-function

Abstract

The authors present an exact expression for the joint count probability in an eight-port homodyne detector used in a recent proposal for a phase measurement by Noh et al. (1992). For a strong local oscillator they relate this joint count probability to the Q-function of the arbitrary input state. This Q-function integrated over radius is the phase distribution corresponding to the phase operators of Noh et al.