scholarly journals Two-Mode Squeezed and Entangled Light Production in Parametric Oscillations

2021 ◽  
Vol 66 (8) ◽  
pp. 674
Author(s):  
D. Ayehu
Keyword(s):  
Photon Number ◽  
Langevin Equations ◽  
Pump Mode ◽  
Light Production ◽  
Squeezed Vacuum ◽  
The Mean ◽  
Parametric Oscillations

We investigate the statistical and quadrature squeezings, as well as the entanglement properties, of a two-mode light generated by non-degenerate parametric oscillations coupled to a two-mode squeezed vacuum reservoir, by employing the solutions of the quantum Langevin equations. It is found that the two-mode light shows the two-mode squeezing and entanglement for all values of the time. Moreover, it is observed that the squeezed vacuum reservoir and the growing amplitude of the pump mode enhance the degrees of two-mode squeezing and entanglement. We have also shown that the amounts of squeezing and entanglement are significant in a region, where the mean photon number is higher, and the photon number correlation is lower.

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.

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.

Comparative analysis of properties for amplified coherent state and amplified squeezed vacuum

2020 ◽  
Vol 34 (33) ◽  
pp. 2050377
Author(s):  
Yan-Bei Cheng ◽  
Sheng-Guo Guan ◽  
Zu-Jian Wang ◽  
Xue-Xiang Xu
Keyword(s):  
Comparative Analysis ◽  
Coherent State ◽  
Amplification Factor ◽  
Annihilation Operator ◽  
Photon Number ◽  
Matrix Elements ◽  
Squeezed Vacuum ◽  
Quadrature Squeezing ◽  
Antibunching Effect ◽  
Analytical Expressions

Two “amplified” quantum states, that is, amplified coherent state (ACS) and amplified squeezed vacuum (ASV), are considered in this paper by applying operator [Formula: see text] on coherent state (CS) and squeezed vacuum (SV), respectively. Here [Formula: see text] [Formula: see text] denotes a amplification factor and [Formula: see text]) denote the creation (annihilation) operator. Along these two lines, we make a comparative analysis of properties for ACS and ASV. The considered properties include density matrix elements, Wigner function, mean photon number, second-order autocorrelation function, and quadrature squeezing. We derive analytical expressions and make numerical simulations for all the properties. The noteworthy results include: (1) the ACS has antibunching and squeezing characters; (2) the ASV will have the bunching and antibunching effect in small initial squeezing.

Signal characters and non-classical properties of quadratically amplified squeezed vacuum

2020 ◽  
pp. 2150028
Author(s):  
Qiang Ke ◽  
Yi-Fan Wang ◽  
Yan-Bei Cheng ◽  
Xue-Xiang Xu
Keyword(s):  
Wigner Function ◽  
Photon Number ◽  
Quadratic Function ◽  
Interaction Parameters ◽  
Intensity Noise ◽  
Number Operator ◽  
Squeezing Effect ◽  
Squeezed Vacuum ◽  
Antibunching Effect ◽  
Noise Squeezing

Based on the squeezed vacuum (SV) and the quadratic function of the photon number operator, we introduce the quadratically amplified squeezed vacuum (QASV) in this paper. We study the intensity, noise, squeezing effect, antibunching effect, and Wigner function of the QASVs. Compared with the SV, the QASVs have distinctive signal characters and possess peculiar non-classical properties in the proper range of interaction parameters.

scholarly journals Optical Bistability in an Optomechanical System with N-Type Atoms under Nonresonant Conditions

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 122
Author(s):  
Yan Gao ◽  
Li Deng ◽  
Aixi Chen
Keyword(s):  
Optical Bistability ◽  
Light Field ◽  
Photon Number ◽  
Optical Switches ◽  
Atomic Ensemble ◽  
Cavity Field ◽  
Bistable Behavior ◽  
Optomechanical System ◽  
The Mean ◽  
Nonlinear Distribution

In this paper, the phenomenon of the optical bistability of a cavity field is theoretically investigated in an optomechanical system containing an N-type atomic ensemble. In this hybrid optomechanical system, the atoms are coupled with two controlling light fields besides coupling with the cavity field. Under the nonresonant condition, we analyze the influences of the coupling strength between cavity and atoms, Rabi frequencies of the controlling light field, the detuning between the controlling light field and atoms, and pump field power on the optical bistable behavior of mean intracavity photon number. The nonlinear distribution of the mean intracavity photon number has a potential application in field optical switches and optical bistable devices.

ANALYSIS OF THE LASER PROCESS WITH THREE DIFFERENT INITIAL STATES

2014 ◽  
Vol 28 (08) ◽  
pp. 1450029 ◽  
Author(s):  
FUYI YOU ◽  
JUNHUA CHEN ◽  
HONGYI FAN
Keyword(s):  
Photon Number ◽  
Entangled State ◽  
State Representation ◽  
Evolution Law ◽  
Laser Process ◽  
Specific Entropy ◽  
Degree Of Coherence ◽  
The Common ◽  
The Mean ◽  
Initial States

We analyze the laser process with three different initial states using the entangled state representation, obtain the evolution law of the mean photon number, the entropy, the specific entropy, the second degree of coherence and the Wigner functions, and find out the common characteristics of these three processes.

ENTANGLEMENT OF A GENERAL FORMALISM Ξ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (09) ◽  
pp. 2269-2283 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom-field entanglement in a system of a Ξ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium and the intensity-dependent coupling functional on the entropy are analyzed.

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.

ENTANGLEMENT OF A GENERAL FORMALISM Λ-TYPE THREE-LEVEL ATOM INTERACTING WITH A SINGLE-MODE FIELD IN THE PRESENCE OF NONLINEARITIES

2009 ◽  
Vol 23 (15) ◽  
pp. 3241-3254 ◽  
Author(s):  
A.-S. F. OBADA ◽  
A. A. EIED ◽  
G. M. ABD AL-KADER
Keyword(s):  
Unitary Operator ◽  
Temporal Evolution ◽  
Initial Density ◽  
Photon Number ◽  
Single Mode ◽  
Field Coupling ◽  
Mode Field ◽  
Level Atom ◽  
The Mean ◽  
Careful Investigation

We investigate the evolution of the atomic quantum entropy and the atom–field entanglement in a system of a Λ-configuration three-level atom interacting with a single-mode field with additional forms of nonlinearities of both the field and the intensity-dependent atom–field coupling. With the derivation of the unitary operator within the frame of the dressed state and the exact results for the state of the system, we perform a careful investigation of the temporal evolution of the entropy. A factorization of the initial density operator is assumed, considering the field to be initially in a squeezed coherent or binomial state. The effects of the mean photon number, detuning, Kerr-like medium, and the intensity-dependent coupling functional on the entropy are analyzed.

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