scholarly journals The Quantum Analysis of Nonlinear Optical Parametric Processes with Thermal Reservoirs

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Tamirat Abebe ◽  
Nebiyu Gemechu ◽  
Chimdessa Gashu ◽  
Kebede Shogile ◽  
Solomon Hailemariam ◽  
...  
Keyword(s):  
Nonlinear Crystal ◽  
Photon Number ◽  
Laser Cavity ◽  
Normal Ordering ◽  
Thermal Reservoir ◽  
Quantum Analysis ◽  
Cavity Radiation ◽  
Cavity Modes ◽  
The Mean ◽  
Parametric Processes

In this paper, employing the stochastic differential equations associated with the normal ordering, the quantum properties of a nondegenerate three-level cascade laser with a parametric amplifier and coupled to a two-mode thermal reservoir are thoroughly analyzed. Particularly, the enhancement of squeezing and the amplification of photon entanglement of the two-mode cavity light are investigated. It is found that the two cavity modes are strongly entangled and the degree of entanglement is directly related to the two-mode squeezing. Despite the fact that the entanglement and squeezing decrease with the increment of the mean photon number of the thermal reservoir, strong amount of these nonclassical properties can be generated for a considerable amount of thermal noise with the help of the nonlinear crystal introduced into the laser cavity. Moreover, the squeezing and entanglement of the cavity radiation enhance with the rate of atomic injection.

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 The Quantum analysis of Nondegenerate Three-Level Laser with Spontaneous Emission and Noiseless Vacuum Reservoir

2018 ◽  
Vol 63 (11) ◽  
pp. 969 ◽  
Author(s):  
T. Abebe
Keyword(s):  
Spontaneous Emission ◽  
Photon Number ◽  
State Level ◽  
Vacuum State ◽  
Langevin Equations ◽  
Normal Ordering ◽  
Squeezed Light ◽  
Quantum Analysis ◽  
Level Laser ◽  
Cavity Radiation

The analysis of quantum properties of the cavity light produced by a coherently driven nondegenerate three-level laser possessing an open cavity and coupled to a two-mode vacuum reservoir is presented. The normal ordering of noise operators associated with the vacuum reservoir is considered. Applying the solutions of the equations of evolution for the expectation values of the atomic operators and the quantum Langevin equations for the cavity mode operators, the squeezing properties, entanglement amplification, and the normalized second-order correlation function of the cavity radiation are described. The three-level laser generates squeezed light under certain conditions, with maximum intracavity squeezing being 50% below the vacuum-state level. Moreover, it is found that the presence of spontaneous emission increases the quadrature squeezing and entanglement and decreses the mean photon number of the two-mode cavity radiation.

Entanglement formulation in the framework of electrically pumped laser cavity

2016 ◽  
Vol 30 (06) ◽  
pp. 1650024
Author(s):  
Solomon Getahun
Keyword(s):  
Decay Constant ◽  
Photon Number ◽  
Laser Cavity ◽  
Entangled State ◽  
Normal Order ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
Electrically Pumped ◽  
The Mean ◽  
Degree Of Entanglement

We analyze electrically pumped atomic cavity coupled to a two-mode vacuum reservoirs via a single-port mirror whose open cavity contains N nondegenerate three-level cascade atoms. We carry out our analysis by putting the noise operators associated with a vacuum reservoir in normal order. It is found that unlike the mean photon number, the quadrature squeezing and the degree of entanglement do not depend on the number of atoms. This implies that the quadrature squeezing and the degree of entanglement of the cavity light do not depend on the number of photons. We have also shown that the light generated by the three-level laser is in a squeezed and entangled state, with maximum quadrature squeezing and degree of entanglement being 50%. Moreover, the mean photon number of the system in which the laser operating at threshold and above threshold does not depend on the spontaneous decay constant.

scholarly journals The Effect of Superposition on the Quantum Features of the Cavity Radiation of a Three-Level Laser

2021 ◽  
Vol 66 (9) ◽  
pp. 761
Author(s):  
D. Ayehu ◽  
A. Chane
Keyword(s):  
Density Operator ◽  
Photon Number ◽  
Quantum Langevin Equation ◽  
Quantum Properties ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
Cavity Radiation ◽  
The Mean ◽  
The Individual ◽  
Light Beams

We study the statistical and squeezing properties of the cavity light produced by a degenerate three-level laser with the use of the solution of the pertinent quantum Langevin equation. Moreover, applying the density operator to the cavity radiation superposition, we investigated the quantum properties of the superposed cavity light beams generated by a pair of degenerate three-level lasers. Superposing the cavity radiation increases the mean and the variance of the photon number without affecting the quadrature squeezing. It is observed that the degree of squeezing of the separate cavity radiation, as well as the superposed cavity radiation, increases with the rate at which the atoms are injected into the cavity. We have also shown that the mean photon number of the superposed cavity radiation is the sum of the mean photon numbers of the individual cavity radiation. However, the variance of the photon number of the superposed cavity radiation turns out to be four times that of the component cavity radiation.

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 Enhancing Steady-State Entanglement Generated by a Nondegenerate Three-Level Laser with Thermal Reservoir

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tamirat Abebe ◽  
Tewodros Yirgashewa ◽  
Abebe Belay
Keyword(s):  
Steady State ◽  
Large Time ◽  
Approximation Scheme ◽  
Atomic State ◽  
Expectation Values ◽  
Normal Ordering ◽  
Time Approximation ◽  
Thermal Reservoir ◽  
Level Laser ◽  
Cavity Radiation

We analyze a nondegenerate three-level cascade laser with an open cavity and coupled to a two-mode thermal reservoir employing the stochastic differential equations for atomic operators associated with the normal ordering. Applying the large-time approximation scheme, we obtain the solutions for the corresponding equations of evolution of the expectation values of atomic operators. Furthermore, employing the resulting solutions, we studied the photon as well as cavity atomic-state entanglement amplification of the cavity radiation.

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 Generation of Entangled Light from a Nondegenerate Three-Level Laser Coupled to a Two-Mode Vacuum Reservoir

2021 ◽  
Vol 66 (7) ◽  
pp. 551
Author(s):  
T. Abebe ◽  
Ch. Gashu
Keyword(s):  
Differential Equations ◽  
Master Equation ◽  
Stochastic Differential Equations ◽  
Normal Ordering ◽  
Quantum Properties ◽  
Level Laser ◽  
Cavity Radiation ◽  
Cavity Modes ◽  
Degree Of Entanglement

The quantum properties of a nondegenerate three-level cascade laser coupled to a two-mode vacuum reservoir are throughly analyzed with the use of the pertinent master equation and stochastic differential equations associated with the normal ordering. Particularly, the enhancement of squeezing and the amplification of photon entanglement of the two-mode cavity light are investigated. It is found that the two cavity modes are strongly entangled, and the degree of entanglement is directly related to the two-mode squeezing. Moreover, the squeezing and entanglement of the cavity radiation enhance with the rate of atomic injection.

NON-DEMOLITIVE PHOTON NUMBER MEASUREMENT VIA χ(2) NONLINEARITY

1999 ◽  
Vol 13 (28) ◽  
pp. 3383-3392 ◽  
Author(s):  
STEFANIA CASTELLETTO ◽  
IVO PIETRO DEGIOVANNI ◽  
MARIA LUISA RASTELLO
Keyword(s):  
Pump Power ◽  
Beam Splitter ◽  
Nonlinear Crystal ◽  
Photon Number ◽  
High Accuracy ◽  
Relative Uncertainty ◽  
Theoretical Evaluation ◽  
High Pump Power ◽  
Coherent Field ◽  
High Pump

The aim of this paper is to present a possible experiment for measuring photon number by a non-demolitive scheme. We show that, in principle, it is possible to deduce the number of photons of an intense pump coherent field by measuring the phase-shift on two frequency conjugated beams due to the interaction with the pump in a nonlinear crystal, which exhibits χ(2) nonlinearity. We perform a theoretical evaluation of the relative uncertainty associated to the photon number measurement, obtaining high accuracy results when high pump power levels, low coupling between pump and crystal and squeezing generators are used. The accuracy obtained are compared with results obtainable with a beam splitter setup.

scholarly journals Quantum analysis of sub harmonic generation with two-mode coherent light

2021 ◽  
Vol 4 (1) ◽  
pp. 026-030
Author(s):  
Getahun Alemayehu ◽  
Dagnew Habtamu
Keyword(s):  
Master Equation ◽  
Harmonic Generation ◽  
Langevin Equation ◽  
Photon Number ◽  
Photon Statistics ◽  
Coherent Light ◽  
Quantum Analysis ◽  
Quadrature Squeezing ◽  
Mean And Variance ◽  
Quadrature Variance

In this work the statistical and squeezing properties of light-driven by sub-harmonic generation with two-mode coherent light are studied. With interaction Hamiltonian of both two-mode coherent and sub harmonic generation, we have driven master equation of system under consideration. From the master equation, the solution of the C-number Langevin equation is derived. It helps us to solve quadrature variance, quadrature squeezing, mean, and variance of photon number for light produced by sub-harmonic generation with the two-mode coherent light state. And the result shows that; the squeezing occurs in plus quadrature with the maximum squeezing of 87%. The photon statistics of the system under consideration is subpoissonian in which both mean & variance are increasing as kappa increase.

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