Dynamical quantum statistical effects in optical parametric processes

We investigate the dynamical and statistical effects of different input states of the electromagnetic field in the travelling wave parametric processes of second harmonic generation and nondegenerate downconversion. Using the phase space techniques of stochastic integration in the positive-P representation, equivalent to a fully quantum mechanical analysis, we consider different input states and show that the effects on the mean field solutions can be quite drastic. We also investigate the effects of the input statistics on the quantum properties of the output fields, finding that a thermal input can actually cause the value of some quantum correlations to increase. (C) 2002 Elsevier Science B.V. All rights reserved.