- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Focusing laser beam through pinhole using bimorph deformable mirror
摘要： As a potential technique to improve channel capacity, orbital angular momentum has been developed in the radio ?eld. In this paper, a novel radio vortex–multiple-input multiple-output (RV-MIMO) system is proposed to provide high capacity in free space. In particular, the vortex channel of the proposed system is modeled. Based on this model, the optimal vortex phase is derived, which results in the optimal capacity of the proposed RV-MIMO system. Simulation results show that the proposed RV-MIMO system could achieve higher capacity than the MIMO system in free space.
关键词： multiple-input multiple-output,radio vortex,vortex phase,Orbital angular momentum
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Evaluation of temperature and humidity on PV module degradation- in field degradation analysis of crystalline silicon module
摘要： In this paper, we demonstrate that the solid cylinder dielectric resonator antenna (CDRA) is a high radiation efficient device to generate orbital angular momentum (OAM) waves with different OAM modes at different frequencies. Theoretical formulations of its radiation fields are deduced in the cylindrical coordinate system, which shows that all components of the electric and magnetic fields have the azimuth dependence of ejm?. A full-wave simulation on a practical size CDRA is then implemented to validate the theoretical derivations. The simulation results show that different separated OAM modes can be obtained at different frequencies. Specifically, the higher order OAM modes are generated at higher electron magnetic modes, which makes CDRA a promising method to overcome the narrow band and multiband issues existing in the design of current OAM devices. Furthermore, a maximum radiation efficiency of 97.1% at 13.3 GHz, and a minimum radiation efficiency of 72.4% at 19.45 GHz are obtained in our simulation, which is a high radiation efficiency feature at the OAM resonant frequencies.
关键词： high radiation efficient.,orbital angular momentum,Cylinder dielectric resonator antenna
更新于2025-09-23 15:19:57
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Performance of Free Space Optical Communication Base on Orbital Angular Momentum with Pointing Errors
摘要： Due to the misalignment of the receiver, the spiral spectrum appears to be extended when the Laguerre-Gaussian beam is applied to atmospheric laser communication. This paper investigates the spiral spectrum spread of the Laguerre-Gaussian beam in the case of receiver misalignment. The analytical expression of Laguerre-Gaussian spiral spectrum under the influence of alignment error is studied by mathematical derivation and simulation. The results show that the detection probability of the original orbital angular momentum (OAM) state varies with the lateral displacement distance and the inclination angle. The bit error rate and channel capacity of each channel were studied to verify the effects of misalignment in multiple OAM communication systems.
关键词： Orbital Angular Momentum,Laguerre-Gaussian beam,Pointing Errors,Free Space Optical Communication,Spiral Spectrum
更新于2025-09-23 15:19:57
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A V-Folded Digital Laser for On-Demand Vortex Beams by Astigmatic Transformation of Hermitea??Gaussian Modes <sup>*</sup>
摘要： A V-folded digital laser using a spatial light modulator (SLM) for intra-cavity loss shaping is exploited to generate Hermite–Gaussian modes with on-demand mode order. With a ??/2 astigmatic mode converter, vortex beams carrying on-demand orbital angular momentum (OAM) with a tunable range from ?11(cid:126) to 12(cid:126) are obtained. The mode order of the HG mode, hence the OAM of the vortex beam, is digitally switched by changing the phase pattern imposed on the SLM without requiring any mechanic alignment of the cavity. This work has great potential applications in various OAM-tunable vortex beams.
关键词： spatial light modulator,vortex beams,orbital angular momentum,Hermite–Gaussian modes,digital laser
更新于2025-09-23 15:19:57
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High-purity orbital angular momentum states from a visible metasurface laser
摘要： Orbital angular momentum (OAM) from lasers holds promise for compact, at-source solutions for applications ranging from imaging to communications. However, conjugate symmetry between circular spin and opposite helicity OAM states (±?) from conventional spin–orbit approaches has meant that complete control of light’s angular momentum from lasers has remained elusive. Here, we report a metasurface-enhanced laser that overcomes this limitation. We demonstrate new high-purity OAM states with quantum numbers reaching ??=?100 and non-symmetric vector vortex beams that lase simultaneously on independent OAM states as much as Δ??=?90 apart, an extreme violation of previous symmetric spin–orbit lasing devices. Our laser conveniently outputs in the visible, producing new OAM states of light as well as all previously reported OAM modes from lasers, offering a compact and power-scalable source that harnesses intracavity structured matter for the creation of arbitrary chiral states of structured light.
关键词： chiral states,metasurface,Orbital angular momentum,visible light,laser
更新于2025-09-23 15:19:57
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Radial-profile-customized orbital-angular-momentum modes: Featuring tailored Gaussian intensity pattern at target receiving plane
摘要： We present the modified-Bessel-superposed Gaussian (MBSG) orbital-angular-momentum (OAM) modes, which can evolve into a field featuring a tailored Gaussian amplitude profile after propagating to a target receiving plane. Analytical expressions for the MBSG OAM modes at a source plane are developed in both the space and wavevector domains. The space- and wavevector-domain representations of the MBSG OAM modes at the source plane are found to share a mathematically formal similarity. We propose to utilize this appealing property for designing a Fourier-transform-based approach to forming the MBSG OAM modes at the source plane. Unlike other commonly reported OAM modes, the receiving-plane field of MBSG OAM modes always exhibits a customized non-ring-shaped Gaussian intensity pattern. This behavior can be exploited, e.g., to benefit the projective phase-flattening OAM measurement and to reduce the turbulence-induced OAM-mode scattering in relevant practical applications.
关键词： Fourier transform,Orbital angular momentum,Optical vortex,Spiral phase front
更新于2025-09-19 17:15:36
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Probability distribution of the orbital angular momentum mode of the ultrashort Laguerre-Gaussian pulsed beam propagation in oceanic turbulence
摘要： By introducing the orbital angular momentum (OAM) eigenfunctions of the pulsed beam and two-frequency mutual coherence function in oceanic turbulence, we establish the received probability distribution of OAM modes of the ultrashort Laguerre-Gaussian pulsed beam propagating through oceanic turbulence. Our results show that the higher rate of dissipation of kinetic energy per unit mass of fluid, larger inner scale, smaller ratio of temperature and salinity contributions to the refractive index spectrum, or lower dissipation rate of the mean-squared temperature will cause the smaller pulse duration by its full-width half-maximum. The pulse duration has a weak dependence on the OAM quantum number. In addition, the smaller OAM quantum number and the larger transmission distance cause the smaller pulse delay. Our results will be useful for vortex pulsed beam in the optical ocean communication and remote sensing.
关键词： Pulse,Vortex beams,Oceanic turbulence,Orbital angular momentum,Optical communication
更新于2025-09-19 17:15:36
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High-Efficiency Planar Reflectarray with Small-size for OAM Generation at Microwave Range
摘要： In this paper, a high-efficiency planar reflectarray with a small size 3.87λ0 × 3.87λ0 is designed, which can effectively convert arbitrary polarized waves to orbital angular momentum (OAM) waves with desired mode number and beam direction. The two concentric rings with a small size 0.38λ0 × 0.38λ0 compose the unit, which can cover the phase shifting range 360o by adjusting the ring radius. Though the developed reflectarray is much smaller than that of published ones, it can produce beams with the similar performance as large antennas. The advantages are as follows: high efficiency 22.6%, which is superior to published OAM reflectarrays, high gain 15.4 dBi, narrow divergence angle 9o, high purity, good stability, polarization insensitivity, planar structure, and easy fabrication. Using this reflective metasurface, we designed the following OAM beams: (1) OAM mode l = 1, 2, 3, 4 at (θ = 0o, φ = 0o). (2) l = 1 at (θ = 45o, φ = 180o). (3) l = 1 at (θ = 45o, φ = 270o). The above advantages are proved by the following analysis: (1) The magnitude and phase distributions in the near field. (2) The purity analysis. (3) The radiation pattern in the far field.
关键词： Orbital angular momentum (OAM),high efficiency,vortex beam,planar reflectarray antenna
更新于2025-09-19 17:15:36
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A study on the effects and visibility of low-order aberrations on laser beams with orbital angular momentum
摘要： Laguerre–Gaussian-like laser beams have been proposed for driving experiments with high-intensity lasers. They carry orbital angular momentum and exhibit a ring-shaped intensity distribution in the far field which make them particularly attractive for various applications. We show experimentally and numerically that this donut-like shape is extremely sensitive to off-axis wavefront deformations. To support our claim, we generate a Laguerre–Gaussian-like laser beam and apply a selection of common low-order wavefront aberrations. We investigate the visibility of those wavefront deformations in the far field. Under use of established tolerance criteria, we determine the thresholds for the applied aberration and compare the findings with simulations for verification.
关键词： tolerance criteria,Laguerre–Gaussian-like laser beams,orbital angular momentum,far field,wavefront aberrations
更新于2025-09-19 17:13:59
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Non-Kolmogorov atmospheric turbulence and orbital angular momentum of entangled states for optical communication
摘要： We extend the theory of detection probabilities of single-photon communication in turbulent atmosphere to the entangled case and derive analytical expressions for detection probabilities. We show that the rotational ?eld correlation in the entangled case cannot be expressed as a straightforward extension from the disentangled case. By considering the orbital angular momentum (OAM) entangled Laguerre-Gaussian (LG) beams for illustration, we explore the e?ect of non-Kolmogorov atmospheric turbulence on the probabilities of both the biphoton detection and the single-photon detection. The entanglement of OAM LG beams contributes positively to the faithful detection probability. The change of maximal crosstalk probability in the detection process is also explored, which displays the non-linear dependence on the crosstalk quantum number.
关键词： Atmospheric turbulence,Orbital angular momentum,Entanglement,Optical communication
更新于2025-09-19 17:13:59