Higher-order squeezing for the codirectional Kerr nonlinear coupler

TL;DR

This paper investigates higher-order squeezing phenomena in a codirectional Kerr nonlinear coupler, revealing how squeezing behavior varies with order and interaction parameters, including revival-collapse effects and the limitations of difference-squeezing.

Contribution

It provides a detailed analysis of higher-order squeezing in Kerr couplers, highlighting the dependence on squeezing order and the significance of sum-squeezing over difference-squeezing.

Findings

Squeezing decreases as the order increases.

Revival-collapse phenomena are observed and become more pronounced with higher order.

Sum-squeezing can surpass higher-order squeezing in magnitude and relate to amplitude-squared squeezing.

Abstract

In this Letter we study the evolution of the higher-order squeezing, namely, $n$th-order single-mode squeezing, sum- and difference-squeezing for the codirectional Kerr nonlinear coupler. We show that the amount of squeezing decreases when $n$, i.e. the squeezing order, increases. For specific values of the interaction parameters squeezing factors exhibit a series of revival-collapse phenomena, which become more pronounced when the value of $n$ increases. Sum-squeezing can provide amounts of squeezing greater than those produced by the $n$th higher-order ($n\geq 2$) squeezing for the same values of interaction parameters and can map onto amplitude-squared squeezing. Further, we prove that the difference-squeezing is not relevant measure for obtaining information about squeezing from this device.