In this communication we investigate the quantum statistics of three harmonic oscillators mutually interacting with each other considering the modes are initially in Fock states. After solving the equations of motion, the squeezing phenomenon, sub-Po
issonian statistics and quasiprobability functions are discussed. We demonstrate that the interaction is able to produce squeezing of different types. We show also that certain types of Fock states can evolve in this interaction into thermal state and squeezed thermal state governed by the interaction parameters.
The evolution of the Schr{o}dinger-cat states in a dissipative parametric amplifier is examined. The main tool in the analysis is the normally ordered characteristic function. Squeezing, photon-number distribution and reduced factorial moments are di
scussed for the single- and compound-mode cases. Also the single-mode Wigner function is demonstrated. In addition to the decoherence resulting from the interaction with the environment (damped case) there are two sources which can cause such decoherence in the system even if it is completely isolated: these are the decay of the pump and the relative phases of the initial cat states. Furthermore, for the damped case there are two regimes, which are underdamped and overdamped. In the first (second) regime the signal mode or the idler mode collapses to a statistical mixture (thermal field).
In this paper we derive the quantum statistical and dynamical properties of nonlinear optical couplers composed of two nonlinear waveguides operating by the second subharmonic generation, which are coupled linearly through evanescent waves and nonlin
early through nondegenerate optical parametric interaction. Main attention is paid to generation and transmission of nonclassical light, based on a discussion of squeezing phenomenon, normalized second-order correlation function, and quasiprobability distribution functions. Initially coherent, number and thermal states of optical beams are considered. In particular, results are discussed in dependence on the strength of the nonlinear coupling relatively to the linear coupling. We show that if the Fock state $|1>$ enters the first waveguide and the vacuum state $|0>$ enters the second waveguide, the coupler can serve as a generator of squeezed vacuum state governed by the coupler parameters. Further, if thermal fields enter initially the waveguides the coupler plays similar role as a microwave Josephson-junction parametric amplifier to generate squeezed thermal light.
In this communication we discuss SU(1,1)- and SU(2)-squeezing of an interacting system of radiation modes in a quadratic medium in the framework of Lie algebra. We show that regardless of which state being initially considered, squeezing can be periodically generated.
We show that a nonlinear asymmetric directional coupler composed of a linear waveguide and a nonlinear waveguide operating by nondegenerate parametric amplification is an effective source of single-mode squeezed light. This is has been demonstrated,
under certain conditions and for specific modes, for incident coherent beams in terms of the quasiprobability functions, photon-number distribution and phase distribution.
We show that a nonlinear asymmetric directional coupler composed of a linear waveguide and a nonlinear waveguide operating by nondegenerate parametric amplification is an effective source of single-mode squeezed light. This is has been demonstrated,
under certain conditions and for specific modes, for incident coherent beams in terms of the quasiprobability functions, photon-number distribution and phase distribution.
In this Letter we describe a new two-mode system, which consists of Kerr-like medium and down conversion process, called the Kerr-down conversion system. Under a certain condition we can obtain an exact solution of the dynamical equations of motion.
For this system we investigate different kinds of quadrature squeezing, e.g., single-mode, two-mode and sum-squeezing. Also we give a more general definition of the principal squeezing. We show that the amounts of nonclassical effects produced by the Kerr-like and down-conversion processes separately are greater than those obtained from the Kerr-down conversion system where both the processes are in competition.
The parametric amplifier with and without the pumping fluctuations of coupling function is considered when the fields are initially prepared in coherent light. The pumping fluctuations are assumed to be normally distributed with time-dependent vari
ance. The effects of antibunching and anticorrelation of photons on the photon distribution, correlation between modes and factorial moments are demonstrated. A possible enhancement of photon antibunching for certain values of initial mean photon numbers is shown and discussed. We have shown also that new states (called modified squeezed vacuum states or even thermal states) can be generated from such an interaction. Further, we have demonstrated that the sum photon-number distribution can exhibit collapses and revivals in the photon-number domain somewhat similar to those known in the Jaynes-Cummings model.
In this paper, we investigate the single mode quantum properties of the codirectional Kerr nonlinear coupler when the frequency mismatch is involved and a condition for an exact solution of equations of motion is fulfilled. Particularly, we investiga
te quadrature and principal squeezing, Wigner function, quadrature distribution, phase distribution and phase variance. We show that the quadrature squeezing and the phase variance can exhibit collapse-revival and collapse-revival-subrevival phenomena, respectively, based on the values of the detuning parameter. Furthermore, we analytically demonstrate that the system can generate cat states, in particular, Yurke-Stoler states.
