Incoherent Pumping Field Research Articles

Spatially hybrid control of entanglement between atom and photon

In this study, we introduced a model utilizing a plasmonic nanostructure to modulate the entanglement between atoms and photons within a V-type atomic medium. This system is influenced by composite optical vortex light (COVL) and two incoherent pumping fields. The plasmonic nanostructure comprises dielectric nanospheres, which have been thoroughly investigated (Phys. Rev. B 106, 035419, 2022). By adjusting the orbital angular momentum (OAM) of COVL, we demonstrate that the nanostructure induces significant spatial variations in the degree of entanglement (DEM). Additionally, incorporating a weak incoherent pumping field affects the DEM profile within the hybrid system. Our findings reveal that the OAM of structured light can govern the spatial dependence of DEM, particularly when quantum interference from the nanostructure and pumping fields surpasses a specific threshold. Furthermore, our results suggest that analyzing the DEM profile's spatial regions can be employed to determine the OAM number of the structured light.

Negative refractive index enhancement with zero absorption in a concentric chiral metal-atomic nanoshell

We investigate the electromagnetic chirality and negative refraction in a concentric nanoshell of a chiral metal sphere and a chiral atomic shell. The medium of the atomic shell with a four-level system is driven by a laser field and an incoherent pump field in a diamond configuration. We show that the electric and magnetic absorption spectra connecting through the chiral coefficients of the respective dipole moments of the two media, produce five and three lines spectral profiles. We explain that the spectral lines separated by dips are the manifestation of the classical (quantum) coherence effect of the wave field excitation in the medium of the metal sphere (atomic shell), and the interaction of the respective dipole moments at the interface of the two media. Furthermore, we show negative refraction with zero absorption without requiring permittivity (ϵ) and permeability (μ) simultaneously negative, where for all values of the incident wavelength, Re [μ] ≈ 1, representing a strong chiral electromagnetic behavior. Consequently, the negative refractive index enhances sufficiently beyond n = −1 for a wide range of parameters depending on the coupling parameters, chiral coefficients, and the radii ratio of the concentric metal-atomic nanoshell.

Goos–Hänchen shifts in a V-type three-level atomic system interacting with squeezed vacuum

This study explores the Goos–Hänchen (GH) shift phenomenon within a cavity hosting a V-type three-level atomic system, engaged with two independent broadband squeezed baths. Our exploration encompasses a thorough analysis of the lateral shifts in both reflected and transmitted light beams, with a focus on the impact of critical factors, i.e, coupling field strength, incoherent pumping field strength, and squeezed vacuum intensity. Our results reveal an interplay of these parameters, resulting in distinctive negative and positive GH shifts in both reflected and transmitted light. In addition, a remarkable enhancement of GH shifts at specific angles of incidence is observed, presenting a wide-ranging modulation across diverse system parameters. This study not only enriches the understanding of the GH shift in complex atomic systems but also highlights the potential for the manipulation of these lateral shifts by fine-tuning key variables of the system, and contributes valuable insights to the broader field of optical phenomena in quantum systems.

Influence of phase diffusion on atomic grating in a three-level ladder-type system in lower-level microwave-driven scheme

In this paper, we consider a scheme for electromagnetically induced grating (EIG) in a three-level ladder-type system. A microwave field of finite bandwidth making a standing-wave pattern is applied on lower levels. In addition, we have also introduced an indirect pump in our system. A weak probe field is then applied to study the effects of phase diffusion associated with the microwave control field on EIG. It is found that phase diffusion associated with the strong microwave control field strongly affect the diffraction. We have incorporated the effect of different system parameters such as the strength of the microwave field, indirect pumping mechanism, interaction length, and detuning in the weak probe field. Interestingly, the stronger microwave control field retrieves the loss in diffraction intensity caused by the phase diffusion. Our results show that the introduction of detuning in the optical probe field results in the enhancement of the phase grating effect. Furthermore, our results show that an optimized indirect pump field can slightly improve the first-order diffraction intensities both in the absence and presence of phase diffusion.

ẢNH HƯỞNG CỦA ĐỘ KẾT HỢP ĐƯỢC TẠO BỞI PHÁT XẠ TỰ PHÁT VÀ BƠM KHÔNG KẾT HỢP LÊN CHUYỂN MẠCH TOÀN QUANG TRONG MÔI TRƯỜNG NGUYÊN TỬ BA MỨC BẬC THANG KHI CÓ MẶT CỦA PHA TƯƠNG ĐỐI

This paper investigates the impact of spontaneously generated coherence (SGC) and relative phase on the propagation of a probe laser pulse in the presence of an incoherent pump field. It was discovered that when the control laser field is turned on, the medium forms an electromagnetically induced transparency (EIT) effect. Hence, the propagation of the probe laser pulse has a like-soliton form/shape. On the contrary, the probe laser field is rapidly attenuated when the control laser field is turned off. This feature allows the creation of a mechanism to turn “off” and “on” the probe laser field through “turning off” and “on” the control laser field, i.e., an all-optical switching mechanism based on EIT. Besides intensity and frequency, the laser field is also characterized by polarization and phase. The EIT has the nature of quantum interference, so it is very sensitive to changes in polarization, especially in the presence of relative phase between laser fields. Therefore, they also significantly affect pulse propagation and optical switching performance. The research results could be helpful for experimental observations or applications in photonic devices such as logic gates, quantum optical information processors, and quantum computers.

Incoherent pumping field and Er3+ ion concentration effects on diffraction pattern of transmitted light in Er3+ doped YAG crystal

The effect of Er[Formula: see text] ion concentration and incoherent pumping field on the Fraunhofer diffraction pattern of the transmitted light beam in Er[Formula: see text]: YAG crystal is discussed. It is shown that under different concentration of Er[Formula: see text] ion in crystal, the energy of the probe light can transfer to the higher orders of the grating. Also, it is shown that the switching from electromagnetically induced grating to electromagnetically induced phase gratin or vice versa can be obtained by different concentration of Er[Formula: see text] ion and incoherent pumping rate in crystal. Moreover, we have found that by replacing the probe light by optical vortex light, the asymmetric diffraction pattern can be obtained by tuning the optical vorticity of optical vortex light. In this case, the asymmetric diffraction pattern can also be controlled at different ion concentration.

Controlling of optical bistability and multistability via two different incoherent processes

In this paper, we investigate the optical bistability (OB) and optical multistability (OM) phenomena for a quantum dot nanostructure via two different mechanisms. The first process is based on the application of the incoherent pumping field while the second one is due to the ratio between the injection and cavity injection rates. We show that the appearance of OB and OM properties in the system depends strongly on the presence of these mechanisms. It is found that OB appears in the presence of both mechanisms, but OM appears only when both mechanisms are present in the system simultaneously. We also study the linear absorption behaviors for the case when OB and OM are observed in the system. It is shown that for the multistable state, the absorption properties of the system are different from the bistable state, which has a strong dependence on incoherent processes.

Tunable nonlinear coherent perfect absorption in cavity QED

We propose and analyze a scheme for tunable coherent perfect absorption (CPA) and near-perfect reflection (near CPR) in a three-level $\mathrm{\ensuremath{\Lambda}}$-type atom-cavity system. With electromagnetically-induced-transparency-type interference induced by a coherent coupling laser, it provides a method of tunable near CPR at two-photon resonance. By virtue of different coupling strengths, CPA can be tuned from the linear regime to the nonlinear or bistable regime at a fixed input-field frequency. In addition, the CPA regime can be switched to the near-CPR regime with variable linear absorption or gain by an incoherent pump field. This work suggests a mechanism for manipulation on perfect absorption and reflection theoretically which can potentially be applied to logical gates and optical switches for coherent optical computing and communication.

Controllable Nonclassical Correlation by an Incoherent Pumping Field in a Λ‐Type Atom‐Cavity System

It is important to generate stable nonclassical correlation and wide-band quantum field in quantum optical communication. In this paper, a scheme is proposed to manipulate the nonclassical intensity correlation of two output fields by a coherent coupling laser and an incoherent pumping field. The core of the scheme is that the coherent field is applied to manipulate the intracavity polaritons, and the incoherent pumping field is used to control the linear absorption and the atomic coherence. With the incoherent field, atoms are repopulated on the excited state | 3 ⟩ $|3\rangle$ . It induces a wide-band zero absorption of a probe field and the negative dispersion that can be used to realize a white-light cavity. In addition, with the increasement of the incoherent pumping rate, the wide-band maximum stable intensity correlation and the nonclassical field with sub-Poissonian distribution are attained, which is verified by the evolution of the second-order correlation of two output channels.

Coherent optical effects in a three-level quantum emitter near a periodic plasmonic nanostructure

We investigate optical effects in a three-level $V$-type quantum system involving two closely situated upper levels (a doublet), interacting with a weak probe field while located near a two-dimensional array of metal-coated dielectric nanospheres. We demonstrate that the presence of the plasmonic nanostructure leads to a significant modification of the absorption and dispersion properties of the quantum $V$ system, yielding either very narrow resonances or induced transparency for the weak probe field. Introducing a weak incoherent pumping field can result in gain with and without population inversion in the quantum system, without the need for a strong coherent pump field. Such a gain can be controlled by varying the distance of the quantum system from the plasmonic nanostructure and by adjusting the amount of incoherent pumping, as well as the doublet splitting. The threshold limits are provided both analytically and numerically for achieving gain with and without inversion using the incoherent pumping. Our analysis paves the way toward further theoretical and experimental studies for mitigating dissipative losses in plasmonic modes when the gain is difficult to achieve due to impractical pumping requirements.

Orbital angular momentum induced bistability in a quantum system

In this article, we have proposed a unique approach to adjust optical bistability (OB) and optical multistability (OM) in a ring cavity inclusive of a three-level quantum system primarily based on quantum mean-field theory. The quantum system interacts with a weak probe light, an incoherent pumping field and a robust coupling light which carries an optical vortex that is an electromagnetic light with optical angular momentum. We confirmed that the real and imaginary parts of the susceptibility of the no-vortex probe light relies on the azimuthal angle and orbital angular momentum (OAM) of the vortex light whilst the quantum interference time period will become important. Moreover, we determined that because of the OAM number of vortex light, the switching from OB to OM is feasible for extraordinary azimuthal angle. These functions of such a three-level quantum system are not stated in any comparable studies.

Two-dimensional electromagnetically induced grating via spontaneously generated coherence and incoherent pump

A new scheme for two-dimensional (2D) electromagnetically induced grating is proposed based on spontaneously generated coherence in a Λ-type atomic system, in which the atom interacts with two orthogonal standing-wave fields and an incoherent pumping field. Due to spatial periodical modulation, the zero absorption or even gain accompanied with large dispersion is obtained in atomic medium, and electromagnetically induced grating is formed. Thus the weak probe field could be diffracted into first-order or high-order directions with high efficiency. The diffraction feature and efficiency of the gratings could be adjusted by the probe field detuning, the interaction length, the incoherent pumping field intensity, and the relative phase as well. The scheme of 2D grating we presented may have some potential application in beam splitting and all-optical switching.

All-optical switching via spontaneously generated coherence, relative phase and incoherent pumping in a V-type three-level system

All-optical switching in a V-type three-level atomic medium is studied and controlled by spontaneously generated coherence (SGC), relative phase of applied fields and incoherent pumping rate. By simultaneously numerical solving the coupled Maxwell–Bloch equations for atom and field on a spatio-temporal grid, we have observed a continuous-wave probe field is switched ON or OFF by periodically modulating the coupling field intensity or the relative phase of applied fields. It also is shows that although the SGC can distort the switching probe pulse, however, under the SGC the response of the medium depends sensitively on the relative phase, and the probe field can be switched synchronous or anti-synchronous with the relative phase. On the other hand, in order to overcome the switching pulse distortion caused by SGC, we have included an incoherent pumping field. By choosing the appropriate phase and pumping rate, the fluctuations of switching probe pulse can be easily overcome. The proposed model can be useful for the design of optical switches and optical storage devices as well as possible experimental implementations.

Giant the Goos-Hänchen shifts with high sensitivity by the interference of incoherent pump field

Giant the Goos-Hänchen shifts with high sensitivity by the interference of incoherent pump field

Role of incoherent pumping field on control of optical bistability in a closed three-level ladder atomic system

In this paper, we analyze the role of incoherent pumping field on the control of optical bistability (OB) via the spontaneously generated coherence (SGC) and relative phase between laser fields in a closed three-level ladder-type atomic system. It is shown that in the presence of incoherent pumping field, the influences of the SGC and the relative phase of the OB behavior become more effective. Simultaneously, the threshold intensity and width of the OB reduce significantly when the incoherent pumping rate increases.

Dissipative solitons in an atomic medium assisted by an incoherent pumping field

This work models the propagation of an optical pulse in a four-level atomic system in the electromagnetically induced transparency regime. By demonstrating that linear and nonlinear optical properties can be externally controlled and tailored by a continuous-wave control laser beam and an assisting incoherent pump field, it is shown how these media can provide an excellent framework to experimentally explore pulse dynamics in the presence of non-conservative terms, either gain or loss. Furthermore, we explore the existence of stable dissipative soliton solutions, testing the analytical results with computational simulations of both the effective (1+1)-dimensional model and the full Maxwell–Bloch system of equations.

Tunable double electromagnetically induced grating with an incoherent pump field

We introduce here double electromagnetically induced grating (DEIG) using a tripod atomic structure, wherein two probe and signal fields with different frequencies simultaneously experience an atomic grating. Properties of presented DEIG can be substantially modified by the detuning of the applied fields. It has also been found that applying an incoherent pump field has a remarkable influence on the high-order diffraction efficiencies. Amplification of travelling weak lights via the incoherent pump field results in large diffraction efficiencies in the first-order and second-order directions. Such a novel scheme might open up the possibility for designing a two-qubit switch that would be advantageous to quantum information processing and quantum networking.

Light drag via electron tunneling and incoherent pumping in semiconductor three-level InAs/GaAs double quantum dot molecules

We theoretically investigate the lateral and rotary light-drag in semiconductor three-level InAs/GaAs double quantum dot molecules. No coherent laser fields are used and the coherence is created by interdot electron tunneling. The effect of interdot electron tunneling on lateral and rotary light-drag is discussed. Moreover, it is shown that applying an incoherent pumping field to the probe transition changes the subluminal to superluminal condition. It is observed that the light polarization state drags opposite and along with the medium motion in superluminal and subluminal propagating regions, respectively.

Investigating tunable bandwidth cavity via three-level atomic systems

We propose a scheme for intracavity electromagnetically induced transparency and white light cavity via three-level Ladder-type Rb atoms. The system is driven by coherent and incoherent fields. Due to the position dependent atom-field interaction, the tunable optical susceptibility of the probe field can be achieved. By using an incoherent pump field and choosing proper parameters, one can control dispersion behavior of the probe field. In weak probe field limit, cavity bandwidth narrowing and broadening could be controlled via atomic systems in different conditions. Assuming the intracavity electromagnetic-induced transparency and the white light cavity conditions, it’s possible to control the susceptibility to satisfy the resonance condition over a wide frequency range. Tuning and controlling bandwidth of the optical cavity may find interesting applications in investigating cavity-QED phenomena and designing novel all-optical devices such as optical switches.

All-optical switching and flip-flop based on dynamically controlled bistability in a V-type atomic system

We have proposed a scheme for all-optical switching and flip-flop based on controllable optical bistability in a simple three-level V-type atomic system assisted by an incoherent pump field. Due to the auxiliary incoherent pump, the atomic population is redistributed in the three levels, and then the absorption-dispersion property and the Kerr nonlinearity of the medium are different from those of the conventional V-type electromagnetically induced transparency system. The results show that both the thresholds and the area (or shape) of the hysteresis loop can be controlled efficiently via the adjustment of either the incoherent pump field or the coupling field. As a result, with a constant cavity input, the output of the optical cavity can be switched between the low- and high-power states of different bistable curves by tuning the optical fields. Based on this effect, we realize all-optical steady-state switching and set-reset flip-flop operation by adding a pulse sequence (positive pulse or set-reset pulse) onto either the incoherent pump field or the coupling field. Such a simple and effective technique of optical switching and flip-flop can find application in all-optical signal processing systems.