Quantum dynamics of a four-channel Kerr nonlinear directional coupler

Quantum dynamics of a four-channel nonlinear directional coupler, based on Kerr effect, was modeled numerically by a set of stochastic differential equations derived using quasiprobability distribution of positive-P\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$P$$\end{document} representation. The modeling of the system is focused on the properties of quadrature evolution below the standard quantum limit, and its comparison with the conventional two-channel device. The results exhibit that a four-channel Kerr coupler provides an effective way to manipulate squeezing, especially in the mixed-mode basis, as compared with the conventional two-channel system—the theme that would make these to be prudent squeezed light source.