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 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.

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 Noise Effect of Vacuum Reservoir on the Dynamics of Three-Level Laser Pumped by Coherent Light

2020 ◽  
Vol 65 (5) ◽  
pp. 385
Author(s):  
M. Molla Gessesse
Keyword(s):  
Single Port ◽  
Photon Number ◽  
Photon Statistics ◽  
Coherent Light ◽  
Noise Effect ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
The Mean

We have investigated the effects of vacuum reservoir noise on the photon statistics and quadrature squeezing of light generated by a three-level laser pumped by coherent light and coupled to a vacuum reservoir via a single-port mirror. We have found that the effect of the vacuum reservoir noise is to increase the photon number variance and to decrease the quadrature squeezing. However, the vacuum reservoir noise has no effect on the mean photon number.

scholarly journals Electrically Pumped Two-Mode Laser Dynamics

2021 ◽  
Vol 66 (3) ◽  
pp. 206
Author(s):  
M. Molla Gessesse
Keyword(s):  
Photon Number ◽  
State Level ◽  
Single Mode ◽  
Langevin Equations ◽  
Frequency Interval ◽  
Quadrature Squeezing ◽  
Level Laser ◽  
Global And Local ◽  
Light Beams ◽  
Global Mean

The statistical and squeezing properties of the cavity light produced by a three-level laser are studied. In the laser, N three-level atoms in an open cavity are coupled with a two-mode vacuum reservoir and are pumped to the top level by means of the electron bombardment. Applying the steady-state solutions of the equations of evolution of the expectation values of the atomic operators and the quantum Langevin equations for the cavity mode operators, we have obtained the global and local photon statistics for single-mode cavity light beams and for two-mode cavity light. It is found that the global mean photon number and the global photon-number variance of the light emitted from the top are greater than those for the light emitted from intermediate level. The cavity lights emitted from the top and intermediate levels can be separately in a chaotic state under certain conditions. However, the two-mode cavity light is in a squeezed state under certain conditions. We have established that the maximum quadrature squeezing of the two-mode cavity light to be about 46% below the coherent-state level. The presence of the vacuum reservoir noise has the effect of increasing the photon-number variance and decreasing the quadrature squeezing of the cavity light but has no effect on the mean photon number. We have shown that the local mean photon number and photon number variance of the cavity light approach the global mean photon number and photon number variance of the cavity light as the frequency interval increases.

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.

Evolution of the number state in laser process

2015 ◽  
Vol 29 (19) ◽  
pp. 1550139
Author(s):  
Fuyi You ◽  
Junhua Chen ◽  
Hongyi Fan ◽  
Wenhui Jiang
Keyword(s):  
Wigner Function ◽  
Density Operator ◽  
Jacobi Polynomials ◽  
Photon Number ◽  
Laser Process ◽  
Number State ◽  
Degree Of Coherence ◽  
The Mean ◽  
Analytic Expression ◽  
Second Degree

We investigate systematically the evolution of the number state in a laser process by deriving the analytic expression of the density operator and putting it into a normal ordered form. The eigenvalue of the density operator is related to Jacobi polynomials. Then we derive the expression for the mean photon number, the second degree of coherence, the entropy, Wigner function and the photoncount distribution. The nonclassicality is discussed by virtue of the negativity of Wigner function. It is found that the Wigner function is always negative for t < t0, which is independent on the parameter m. On the other hand, the condition for the second degree of coherence larger than 1 is dependent on the parameter m.

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 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.

scholarly journals Interaction of Two-Level Atoms with a Single-Mode Quantized Radiation Field

2021 ◽  
Vol 66 (7) ◽  
pp. 570
Author(s):  
M. Molla Gessesse
Keyword(s):  
Photon Number ◽  
Single Mode ◽  
Frequency Interval ◽  
Quantum Langevin Equation ◽  
Level Laser ◽  
Local Mean ◽  
Quantized Radiation Field ◽  
Global And Local ◽  
Steady State Solutions ◽  
Quadrature Variance

We have studied the statistical and squeezing properties of the cavity light generated by a two-level laser. This optical system contains N two-level atoms available in a cavity coupled to a single-mode vacuum reservoir. They are pumped to the top level from the bottom level by means of the electron bombardment. Applying the steady-state solutions of the equations of evolution of the expectation values of the atomic operators and the quantum Langevin equation, we obtained the global and local photon statistics of the single-mode light beam. We have found that, for the two-level laser operating well above the threshold, the uncertainties in the plus and minus quadratures are equal and satisfy the minimum uncertainty relation. In view of this, we have identified the light generated by the laser operating well above threshold to be coherent. On the other hand, the light generated by the laser operating at threshold is found to be chaotic. From the obtained results, we have also observed that a large part of the local mean photon number, the local photon number variance, and the local quadrature variance are confined in a relatively narrow frequency interval.

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.

Sign in / Sign up

Export Citation Format

Share Document