Azimuthal modulation of electromagnetically induced grating using structured light.
TL;DR: In this paper, a two-dimensional Electromagnetic-Induced Grating (EIG) was proposed for diffraction grating in a three-level Lambda-type atomic system with a weak probe field and two simultaneous position-dependent coupling fields.
Abstract: We propose a theoretical scheme for creating a two-dimensional Electromagnetically Induced Grating in a three-level $$\Lambda $$
-type atomic system interacting with a weak probe field and two simultaneous position-dependent coupling fields—a two dimensional standing wave and an optical vortex beam. Upon derivation of the Maxwell wave equation, describing the dynamic response of the probe light in the atomic medium, we perform numerical calculations of the amplitude, phase modulations and Fraunhofer diffraction pattern of the probe field under different system parameters. We show that due to the azimuthal modulation of the Laguerre–Gaussian field, a two-dimensional asymmetric grating is observed, giving an increase of the zeroth and high orders of diffraction, thus transferring the probe energy to the high orders of direction. The asymmetry is especially seen in the case of combining a resonant probe with an off-resonant standing wave coupling and optical vortex fields. Unlike in previously reported asymmetric diffraction gratings for PT symmetric structures, the parity time symmetric structure is not necessary for the asymmetric diffraction grating presented here. The asymmetry is due to the constructive and destructive interference between the amplitude and phase modulations of the grating system, resulting in complete blocking of the diffracted photons at negative or positive angles, due to the coupling of the vortex beam. A detailed analysis of the probe field energy transfer to different orders of diffraction in the case of off-resonant standing wave coupling field proves the possibility of direct control over the performance of the grating.
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TL;DR: In this paper , the performance of a symmetric two-dimensional electromagnetically induced grating produced in a four-level $N$-type atomic scheme was investigated, which interacts with a weak probe field and two simultaneous coupling fields: a 2D standing wave and a composite optical vortex beam.
Abstract: We investigate the performance of a symmetrical two-dimensional electromagnetically induced grating produced in a four-level $N$-type atomic scheme, which interacts with a weak probe field and two simultaneous coupling fields: a two-dimensional standing wave and a composite optical vortex beam. Based on the Maxwell wave equation, we study numerically the behavior of the amplitude, the phase modulations, as well as the probe field diffraction intensities of different order under various conditions for the coupling field detunings and the orbital angular momentum of the Laguerre-Gaussian field. The different orders of diffraction are altered when the azimuthal angle of the composite vortex light changes, thus producing a two-dimensional symmetric grating which transfers the probe energy to higher orders of diffraction. A detailed analysis of the probe field energy transfer to these different orders proves the possibility for direct control over the performance of the grating.
20 citations
12 citations
TL;DR: In this article , a new theoretical scheme for two-dimensional (2D) electromagnetically induced grating (EIG) is proposed in a three-level Ξ-type atomic system.
Abstract: A new theoretical scheme for two-dimensional (2D) electromagnetically induced grating (EIG) is proposed in a three-level Ξ-type atomic system. The system is driven by a weak probe field and two position-dependent coupling fields—a 2D standing-wave field and a vortex field. Due to lopsided spatial modulation of the vortex Laguerre–Gaussian field, the weak probe light could be diffracted into different domains and asymmetric 2D EIG is formed. The result shows that the diffraction patterns and efficiency could be effectively modulated by the azimuthal parameter of the vortex field. Also, the system parameters such as the probe field detuning, the intensity of the vortex field, and the interaction length could be used to regulate the diffraction properties of the 2D EIG effectively. The scheme of asymmetric 2D EIG may have some potential application in all-optical information processing and the design of quantum devices.
4 citations
3 citations
TL;DR: In this paper , the authors reviewed the nonlinear frequency conversion of vortex lasers with a focus on sum frequency generation stimulated Raman scattering, and optical parametric oscillators, and the characteristics of the topological charge transfer and output beam profiles of different frequency conversion were discussed.
Abstract: Optical vortices are optical fields that possess a helical phase and orbital angular momentum, which have found the application in micromanipulation, optical communication, orbital angular momentum entanglement, super-resolution imaging, metrology, etc. The urgent need for the wide spreading applications of vortex lasers is to increase the wavelength versatility. In this study, the nonlinear frequency conversion of vortex lasers with a focus on sum frequency generation stimulated Raman scattering, and optical parametric oscillators were meticulously reviewed. The characteristics of the topological charge transfer and output beam profiles of different frequency conversion were discussed. As the precise tuning of optical fields in both temporal and spatial domains shall be the trend of future studies, it is our hope that this review shall serve as a reference for future research. Combining these techniques with the streaming methods to produce optical vortices, i.e., annular pump, off-axis pump, reflection mirror with defect spots, spherical aberration, and birefringence, it is advisable to expand the wavelength and fill the wavelength gap in the ultraviolet, visible, and infrared bands.
2 citations
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TL;DR: In this paper, the authors consider the atomic dynamics and the optical response of the medium to a continuous-wave laser and show how coherently prepared media can be used to improve frequency conversion in nonlinear optical mixing experiments.
Abstract: Coherent preparation by laser light of quantum states of atoms and molecules can lead to quantum interference in the amplitudes of optical transitions. In this way the optical properties of a medium can be dramatically modified, leading to electromagnetically induced transparency and related effects, which have placed gas-phase systems at the center of recent advances in the development of media with radically new optical properties. This article reviews these advances and the new possibilities they offer for nonlinear optics and quantum information science. As a basis for the theory of electromagnetically induced transparency the authors consider the atomic dynamics and the optical response of the medium to a continuous-wave laser. They then discuss pulse propagation and the adiabatic evolution of field-coupled states and show how coherently prepared media can be used to improve frequency conversion in nonlinear optical mixing experiments. The extension of these concepts to very weak optical fields in the few-photon limit is then examined. The review concludes with a discussion of future prospects and potential new applications.
4,218 citations
TL;DR: In this paper, the authors demonstrate the ability to multiplex and transfer data between twisted beams of light with different amounts of orbital angular momentum, which provides new opportunities for increasing the data capacity of free-space optical communications links.
Abstract: Researchers demonstrate the ability to multiplex and transfer data between twisted beams of light with different amounts of orbital angular momentum — a development that provides new opportunities for increasing the data capacity of free-space optical communications links.
3,556 citations
TL;DR: Electromagnetic induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation EIT may also be used, but under more limited conditions, to eliminate optical self-focusing and defocusing and to improve the transmission of laser beams through inhomogeneous refracting gases and metal vapors, as figure 1 illustrates.
Abstract: Electromagnetically induced transparency is a technique for eliminating the effect of a medium on a propagating beam of electromagnetic radiation EIT may also be used, but under more limited conditions, to eliminate optical self‐focusing and defocusing and to improve the transmission of laser beams through inhomogeneous refracting gases and metal vapors, as figure 1 illustrates The technique may be used to create large populations of coherently driven uniformly phased atoms, thereby making possible new types of optoelectronic devices
3,269 citations
Book•
01 Jan 1975
TL;DR: In this paper, classical theory of resonance optics, the optical Bloch equations, two-level atoms in steady fields, pulse propagation experiments, saturation phenomena, quantum electrodynamics and spontaneous emission are discussed.
Abstract: Topics covered include: classical theory of resonance optics; the optical Bloch equations; two-level atoms in steady fields; pulse propagation; pulse propagation experiments; saturation phenomena; quantum electrodynamics and spontaneous emission; N-atom spontaneous emission and superradiant decay; and photon echoes. (GHT)
3,000 citations
TL;DR: The viability of using the orbital angular momentum (OAM) of light to create orthogonal, spatially distinct streams of data-transmitting channels that are multiplexed in a single fiber is demonstrated and suggest that OAM could provide an additional degree of freedom for data multiplexing in future fiber networks.
Abstract: Internet data traffic capacity is rapidly reaching limits imposed by optical fiber nonlinear effects Having almost exhausted available degrees of freedom to orthogonally multiplex data, the possibility is now being explored of using spatial modes of fibers to enhance data capacity We demonstrate the viability of using the orbital angular momentum (OAM) of light to create orthogonal, spatially distinct streams of data-transmitting channels that are multiplexed in a single fiber Over 11 kilometers of a specially designed optical fiber that minimizes mode coupling, we achieved 400-gigabits-per-second data transmission using four angular momentum modes at a single wavelength, and 16 terabits per second using two OAM modes over 10 wavelengths These demonstrations suggest that OAM could provide an additional degree of freedom for data multiplexing in future fiber networks
2,343 citations