PHASE PROPERTIES OF THE ASYMMETRIC NONLINEAR COUPLER

We examine phase properties of a contradirectional nonlinear asymmetri c coupler. We derive the phase distribution using the concept of phase space. An interesting behaviour of the linear mode, namely bifurcatio n of a distribution, phase shift, experienced during its propagation a nd phase switching are demonstrated. It is shown that light initially in the coherent state approximately maintains its phase properties dur ing amplification although its Poissonian photon-number statistics are not conserved. Finally, thermal noise in the linear mode can be reduc ed and squeezing of the phase fluctuations under the level of those fo r the coherent state with appropriately chosen parameters of the proce ss can be obtained.