Quadrature and polarization squeezing in a dispersive optical bistability model

Abstract

We theoretically study quadrature and polarization squeezing in dispersive optical bistability through a vectorial Kerr cavity model describing a nonlinear cavity filled with an isotropic χ (3) medium in which self-phase and cross-phase modulation, as well as four-wave mixing, occur. We derive expressions for the quantum fluctuations of the output field quadratures as a function of which we express the spectrum of fluctuations of the output field Stokes parameters. We pay particular attention to study how the bifurcations affecting the non-null linearly polarized output mode squeezes the orthogonally polarized vacuum mode, and show how this produces polarization squeezing.

Noncritical quadrature squeezing through spontaneous polarization symmetry breaking

“…Finally, note that although one of the Stokes parameters is free from quantum fluctuations in the light exiting the cavity (the twin beams' intensity difference), this is not enough to claim for polarization squeezing as further conditions must be satisfied [17,18].…”

Limiting effects of geometrical and optical nonlinearities on the squeezing in optomechanics

“…These internal vibrations increase for large bending and contribute to the re-thermalization of the resonator at the low temperatures. These effects are reversed to those of the Kerr nonlinearities which improve the squeezing [8]. For δx 2 m ≈ 4.44, β is evaluated to be about 0.88 (see Fig.…”

“…Squeezed states are nonclassical states in which the variance of at least one of the canonical variables is reduced below the noise level of zero point fluctuations. To generate squeezed states, the common technique consists to use an optical cavity filled with a nonlinear Kerr medium which is fed with an external pumping field [8]. With the recent advances in cooling techniques for nano scale optomechanical systems, various setups have been designed for quantum ground state engineering of mechanical mirrors with highly squeezed states of light [9,10,11,12,13,14].…”

Polarization rotation of light propagating through a medium with efficient four-wave mixing and cross-phase modulation

“…It was proposed previously that Zeeman degeneracy of two-level atoms can enhance FWM as well as XPM processes [20][21][22] and later on a few extensive studies were performed [23][24][25][26]. Also, the same system was proposed [27][28][29][30][31][32] and demonstrated [33][34][35][36] to generate a squeezed vacuum state and polarization squeezed states. Similar multi-wave mixing processes enhanced by the atomic coherence in a multi-Zeeman-sublevel atomic system [37,43] have also been discussed in recent years.…”