scholarly journals Two-Level Atom with Squeezed Light from Optical Parametric Oscillators

2018 ◽  
Vol 63 (7) ◽  
pp. 600 ◽  
Author(s):  
T. Abebe ◽  
N. Gemechu
Keyword(s):  
Power Spectrum ◽  
Cavity Mode ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Fluorescent Light ◽  
Parametric Oscillators ◽  
Quantum Langevin Equation ◽  
Level Atom ◽  
Upper Level ◽  
Correlation Properties

The dynamics of a coherently driven two-level atom with parametric amplifier and coupled to a vacuum reservoir is analyzed. The combination of the master equation and the quantum Langevin equation is presented to study the quantum properties of light. By using these equations, we have determined the time evolution of the expectation values of the cavity mode and atomic operators. Moreover, with the aid of these results, the correlation properties of noise operators, and the large-time approximation scheme, we calculate the mean photon number, power spectrum, second-order correlation function, and quadrature variances for the cavity-mode light and fluorescence. It is found that the half-width of the power spectrum for the fluorescent light in the presence of a parametric amplifier increases, while it decreases for the cavity-mode light. Moreover, we have found the probability for the atom to be in the upper level in the presence of a parametric amplifier.

scholarly journals Coherently Driven N Number of Degenerate Three-Level Atoms with Parametric Amplifier

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Tamirat Abebe ◽  
Chimdessa Gashu ◽  
Nebiyu Gemechu
Keyword(s):  
Characteristic Function ◽  
Cavity Mode ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Frequency Interval ◽  
Normal Order ◽  
Quantum Langevin Equation ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
The Mean

We have analyzed the squeezing and statistical properties of the cavity light beam produced by a coherently driven degenerate three-level laser with a degenerate parametric amplifier (DPA) in an open cavity and coupled to a vacuum reservoir via a single-port mirror. We have carried out our analysis by putting the noise operators associated with the vacuum reservoir in normal order. Applying the solutions of the equations of evolution for the expectation values of the atomic operators and the quantum Langevin equation for the cavity mode operator, the mean photon number and the quadrature squeezing of the cavity light are calculated. And a large part of the mean photon number is confined in a relatively small frequency interval. Furthermore, we also obtain the antinormally ordered characteristic function defined in the Heisenberg picture. With the aid of the resulting characteristic function, we determine the Q function which is then used to calculate the photon number distribution.

scholarly journals A Bright Entanglement and Squeezing Generated by an External Pumping Radiation in a Correlated Emission Laser

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Chimdessa Gashu
Keyword(s):  
Cavity Mode ◽  
Nonlinear Crystal ◽  
Energy State ◽  
Photon Number ◽  
Statistical Properties ◽  
Intensity Difference ◽  
Normal Ordering ◽  
Cavity Modes ◽  
Correlation Properties ◽  
Correlated Emission

The quantum and statistical properties of light generated by an external classical field in a correlated emission laser with a parametric amplifier and coupled to a squeezed vacuum reservoir are investigated using the combination of the master and stochastic differential equations. First, the solutions of the cavity-mode variables and correlation properties of noise forces associated to the normal ordering are obtained. Next, applying the resulting solutions, the mean photon number of the separate cavity modes and their crosscorrelation, smallest eigenvalue of the symplectic matrix, mean photon number, intensity difference fluctuation, photon number variance, and intensity correlation are derived for the cavity-mode radiation. The entanglement produced is studied employing the logarithmic negativity criterion. It is found that pumping atoms from the lower energy state to excited state, introducing the nonlinear crystal into the cavity and coupling the system to a biased noise fluctuation, generate a bright and strong squeezing and entanglement with enhanced statistical properties although the atoms are initially in the ground state.

scholarly journals Interaction of Two-Level Atom with Squeezed Vacuum Reservoir

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Tamirat Abebe ◽  
Demissie Jobir ◽  
Chimdessa Gashu ◽  
Ebisa Mosisa
Keyword(s):  
Correlation Function ◽  
Power Spectrum ◽  
Decay Constant ◽  
Steady State Solution ◽  
Expectation Values ◽  
Quantum Properties ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Atom Interaction ◽  
Upper Level

In this paper, the quantum properties of a two-level atom interaction with squeezed vacuum reservoir is throughly analyzed. With the aid of the interaction Hamiltonian and the master equation, we obtain the time evolution of the expectation values of the atomic operators. Employing the steady-state solution of these equations, we calculate the power spectrum and the second-order correlation function for the interaction of two-level atom with squeezed vacuum reservoir. It is found that the half width of the power spectrum of the light increases with the squeeze parameter, r . Furthermore, in the absence of decay constant and interaction time, it enhances the probability for the atom to be in the upper level.

scholarly journals Enhanced Squeezing and Entanglement in Nondegenerate Three-Level Laser Coupled to Squeezed Vacuum Reservoir

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ebisa Mosisa
Keyword(s):  
Differential Equations ◽  
Cavity Mode ◽  
Photon Number ◽  
Intensity Difference ◽  
Normal Ordering ◽  
Symplectic Matrix ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Level Laser ◽  
The Mean

Squeezing and entanglement of a two-mode cascade laser, produced by a three-level atom which is initially prepared by a coherent superposition of the top and bottom levels then injected into a cavity coupled to a two-mode squeezed vacuum reservoir is discussed. I obtain stochastic differential equations associated with the normal ordering using the pertinent master equation. Making use of the solutions of the resulting differential equations, we determined the mean photon number for the cavity mode and their correlation, EPR variables, smallest eigenvalue of the symplectic matrix, intensity difference fluctuation, and photon number correlation. It is found that the squeezed vacuum reservoir increases the degree of the statistical and nonclassical features of light produced by the system. Furthermore, using the criteria developed by logarithm negativity and Hillery-Zubairy criteria, the quantum entanglement of the cavity mode is quantified. It is found that the degree of the entanglement for the system under consideration increases with the squeezing parameter of the squeezed vacuum reservoir.

scholarly journals Generation of Bright and Entangled Light from a Nondegenerate Three-Level Laser with Parametric Amplifier and Coupled to Thermal Reservoir

2021 ◽  
Vol 66 (3) ◽  
pp. 185
Author(s):  
T. Abebe ◽  
Ch. Gashu ◽  
E. Mosisa
Keyword(s):  
Small Amplitude ◽  
Photon Number ◽  
Parametric Amplifier ◽  
Thermal Reservoir ◽  
Quadrature Squeezing ◽  
Photon Pairs ◽  
Level Laser ◽  
The Mean ◽  
Correlation Properties ◽  
High Degree

The detailed analysis of the two-mode quadrature squeezing and statistical properties of light generated by a nondegenerate three-level laser which has a parametric amplifier and coupled with a thermal reservoir is executed. The combination of the master equation and the stochastic differential equation is presented to study the nonclassical features of the light generated by the quantum system. Moreover, with the aid the resulting solutions together with the correlation properties of noise operators, we calculated the quadrature squeezing, entanglement, and mean number of photon pairs of the cavity light. It is found that the external small-amplitude driving radiation induces a strong correlation between the top and bottom states of three-level atoms to produce a high degree of squeezing. Moreover, the presence of a parametric amplifier is found to enhance the degree of squeezing of the cavity light. We have also established that an increase in the mean thermal photon number appears to degrade the squeezing, but enhances the mean number of photon pairs of the cavity light.

scholarly journals Regime of small number of photons in the cavity for a singleemitter laser

2021 ◽  
Vol 2103 (1) ◽  
pp. 012158
Author(s):  
N V Larionov
Keyword(s):  
Differential Equation ◽  
Exact Solutions ◽  
Master Equation ◽  
Cavity Mode ◽  
Photon Number ◽  
System Of Equations ◽  
Equation Approach ◽  
Master Equation Approach ◽  
Single Emitter ◽  
Analytical Expressions

Abstract The model of a single-emitter laser generating in the regime of small number of photons in the cavity mode is theoretically investigated. Based on a system of equations for different moments of the field operators the analytical expressions for mean photon number and photon number variance are obtained. Using the master equation approach the differential equation for the phase-averaged quasi-probability Q is derived. For some limiting cases the exact solutions of this equation are found.

scholarly journals ANTIBUNCHING EFFECT OF TWO PHOTON FLUORESCENT LIGHT FOR A TWO LEVEL ATOM IN A SQUEEZED VACUUM

1997 ◽  
Vol 46 (9) ◽  
pp. 1718
Author(s):  
FENG XUN-LI ◽  
HE LIN-SHENG ◽  
LIU YONG-LIANG
Keyword(s):  
Fluorescent Light ◽  
Two Photon ◽  
Squeezed Vacuum ◽  
Level Atom ◽  
Antibunching Effect

The influence of the classical homogenous gravitational field on interaction of a three-level atom with a single mode cavity field

2015 ◽  
Vol 29 (29) ◽  
pp. 1550175 ◽  
Author(s):  
N. H. Abd El-Wahab ◽  
Ahmed Salah
Keyword(s):  
Electromagnetic Field ◽  
Gravitational Field ◽  
Photon Number ◽  
Single Mode ◽  
Temporal Behavior ◽  
Cavity Field ◽  
Text Type ◽  
Level Atom ◽  
The Mean ◽  
Single Mode Cavity

We study the interaction between a single mode electromagnetic field and a three-level [Formula: see text]-type atom in the presence of a classical homogenous gravitational field when the atom is prepared initially in the momentum eigenstate. The model includes the detuning parameters and the classical homogenous gravitational field. The wave function is calculated by using the Schrödinger equation for a coherent electromagnetic field and an atom is in its excited state. The influence of the detuning parameter and the classical homogenous gravitational field on the temporal behavior of the mean photon number, the normalized second-order correlation function and the normal squeezing is analyzed. The results show that the presence of these parameters has an important effect on these phenomena. The conclusion is reached and some features are given.

LONG RANGE CORRELATION PROPERTIES OF AFTERSHOCK RELAXATION SIGNALS

Fractals ◽  
1995 ◽  
Vol 03 (04) ◽  
pp. 839-847 ◽  
Author(s):  
A. VESPIGNANI ◽  
A. PETRI ◽  
A. ALIPPI ◽  
G. PAPARO ◽  
M. COSTANTINI
Keyword(s):  
Time Series ◽  
Acoustic Emission ◽  
Statistical Analysis ◽  
Power Spectrum ◽  
Power Law ◽  
Amplitude Distribution ◽  
Relaxation Processes ◽  
Critical Dynamics ◽  
Range Correlation ◽  
Correlation Properties

Relaxation processes taking place after microfracturing of laboratory samples give rise to ultrasonic acoustic emission signals. Statistical analysis of the resulting time series has revealed many features which are characteristic of critical phenomena. In particular, the autocorrelation functions obey a power-law behavior, implying a power spectrum of the kind 1/f. Also the amplitude distribution N(V) of such signals follows a power law, and the obtained exponents are consistent with those found in other experiments: N(V) dV≃V–γ dV, with γ=1.7±0.2. We also analyzed the distribution N(τ) of the delay time τ between two consecutive acoustic emission events. We found that a N(τ) distribution rather close to a power law constitutes a common feature of all the recorded signals. These experimental results can be considered as a striking evidence for a critical dynamics underlying the microfracturing processes.

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