Eur. Phys. J. Plus (2022) 137: 91
https://doi.org/10.1140/epjp/s13360-021-02302-1

Regular Article

Quantum squeezing in coupled waveguide networks with quadratic and qubic nonlinearity

¹ Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM) Perak, Tapah Campus, Tapah Road, 35400, Perak, Malaysia
² Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), 40450, Shah Alam, Selangor, Malaysia
³ Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA (UiTM) Perak, Tapah Campus, Tapah Road, 35400, Perak, Malaysia

^a rafaeljulius@uitm.edu.my

Received: 23 July 2021
Accepted: 19 December 2021
Published online: 7 January 2022

Abstract

This study demonstrates that coupled waveguide networks with quadratic and cubic nonlinearity mediated by a linear waveguide allow for the generation, enhancement and transmission of squeezed light on a single-mode and multi-mode basis. The time evolution of the density matrix could be mapped to the corresponding Fokker–Planck equation of a classical quasiprobability distribution using the positive P representation of the phase space. Using the Langevin stochastic equation, we examine the scenarios where the system functions at varied evanescent coupling profiles, coupled modes interaction, competing nonlinear response and ultimately when the second harmonic generation and self-action Kerr interaction are present or absent. We analyze the behavior of squeezing and how the evolution is affected by the presence of coupled nonlinearity. We show that the interplay of linear and nonlinear effects in coherently driven coupled waveguide networks has the potential to be a valuable source of squeezed light.