Quantum-phase properties of the Kerr couplers

We use the concept of phase space and Husimi quasidistribution to derive jo int-phase probability distribution and quantum-phase properties for the Ker r couplers. The exact numerical as well as approximate analytical solutions of the Schrodinger equation are found. The spatial development of the sing le-mode phase distributions and phase-difference distribution is demonstrat ed. The Fourier coefficients of the phase distributions are introduced and employed to describe quantum-phase behaviour, It is shown that the phase-di fference evolution is closely connected to an energy exchange between two w aveguides, which form the coupler. The collapses and revivals of the mean p hoton number oscillations are due to the bifurcation of the phase-differenc e probability distribution, which has a two-fold symmetry in the interval o f collapse. (C) 1999 Elsevier Science B.V. All rights reserved.