Journal of Modern Optics
Quantum travelling-wave analysis of a quasi-phase-matched parametric amplifier
Chao Zhao, W. H. Tan
Abstract
The paper describes a phase-mismatched Fokker–Planck equation formulation for parametric amplification in periodically inverted nonlinear media. An analytical solution of the phase-mismatched Fokker–Planck equation and the amplitude quantum fluctuation after passing through the quasi-phase-matched (QPM) device are obtained. The calculated results for the QPM device conform to that of the Langevin equation in the case of no loss k=0, and give a general solution for k≠0. From this one can derive knowledge of the dependence of squeezing on the loss coefficient k and make a comparison between the QPM device and a phase matched device at the threshold k=ε0.