Quantum-phase properties of the Kerr couplers

We use the concept of phase space and Husimi quasidistribution to derive joint-phase probability distribution and quantum-phase properties for the Kerr couplers. The exact numerical as well as approximate analytical solutions of the Schrodinger equation are found. The spatial development of the single-mode phase distributions and phase-difference distribution is demonstrated. The Fourier coefficients of the phase distributions are introduced and employed to describe quantum-phase behaviour, It is shown that the phase-difference evolution is closely connected to an energy exchange between two waveguides, which form the coupler. The collapses and revivals of the mean photon number oscillations are due to the bifurcation of the phase-difference probability distribution, which has a two-fold symmetry in the interval of collapse. (C) 1999 Elsevier Science B.V. All rights reserved.