Generation Of Airy Beams Research Articles

Generation of Spin‐Dependent Accelerating Beam with Geometric Metasurface

AbstractAiry beam holds great promise for wide applications because of its unique features of being diffraction‐free, self‐accelerating, and self‐healing. Much efforts are devoted to develop concise and efficient methods to generate and manipulate accelerating Airy beams. In this paper, a novel method is proposed to generate single or paired Airy beams by encoding the geometric phase of dielectric metasurface. Cubic phase, together with a linearly gradient phase, is imposed on the metasurface to control the acceleration and initial launching velocity of accelerating Airy beams. Spin‐dependent geometric phase facilitates the generation of spin‐dependent Airy beams by simply controlling the polarization of incident light. High quality of the generated Airy beam is testified by characterization of its diffraction‐free, self‐accelerating, and self‐healing propagation. Despite the loss for silicon in visible region, generation efficiency as high as 63% is achieved for the metasurface Airy beam generator. The results demonstrate the possibility to manipulate complex structured optical field with all‐dielectric metasurface and broaden the potential application of Airy beams into compact and integrated systems.

Temporal analysis of Airy beam propagation in photorefractive media

We theoretically examine the temporal behavior of Airy beams and their interactions in photorefractive medium with the split-step Fourier method. Simulations indicate that Airy beam propagations are effectively controlled by the illumination time. Under saturated nonlinearity, the beam intensity maintains the soliton profile at the output section, and its propagation direction is modulated by the beam amplitude. Moreover, the temporal behavior of Airy beam interactions varies greatly with illumination time, especially for the in-phase case. Breathing solitons and parallel soliton pairs are produced in-phase and out-of-phase, respectively. These results are potentially useful in all-optical device applications.

Propagation dynamics of finite-energy Airy beams in nonlocal nonlinear atomic vapor

We investigate the propagation properties of finite-energy Airy beams in nonlocal nonlinear atomic vapor. The nonlocality is caused by the transportation of optically excited atoms and described with a Green function. By conducting numerical simulation on Airy beams in the case of one-dimension, two-dimensions, and ring geometry, respectively, we find that the beams have a more stable shape and a longer propagation distance in the presence of nonlocality. The results show that the nonlocality can slow down the beams’ distortion induced by the self-focusing effect and contributes to a more stable propagation of Airy beams in the nonlinear media.

Steering the propagation of finite-energy Airy beam by spatial phase modulation

Abstract The effect of spatial phase modulation on the propagation of finite-energy Airy beam (FEAB) is investigated. A sinusoidal phase is introduced on a FEAB and the propagation behavior is analyzed in Kerr medium by numerical simulation. The basic idea is to impose a sinusoidal phase modulator on the beam before entering the medium. It is found that optical amplitude, spatial modulation frequency, phase shift and truncated factor have important impact on the propagation behavior. Deflection, soliton-like propagation, beam splitting and periodical oscillation can be easily realized by choosing different values of modulation parameters. These results may found novel applications in beam splitter, modulator and other optical steering application for Airy beams.

Shaping Airy beams by using tunable polarization holograms

Optical beam shaping has emerged as an important tool in optics and photonics applications. Here we present the generation of Airy beams by means of the spatial-light-modulator-assisted polarization holography technique. The polarization holograms (PHs) are recorded in a polarization-sensitive nematic liquid crystal cell. By exploiting the advantages of the PH’s diffraction properties, such as the achromatic behavior, the high diffraction efficiency, and the polarization dependence, we experimentally generated Airy beams with diffraction efficiency of 91% at a wavelength of 633 nm.

Propagation trajectory measurement and autofocusing generation of Airy beams using digital propagation.

We present a method of measuring the propagation trajectory of Airy beams using digital propagation based on the theory of angular spectrum. The dependence of the transverse displacement of Airy beams on artificial propagation distance in phase masks is investigated with no motion of imaging apparatus. The parabolic propagation trajectory is experimentally verified, which is consistent with theoretical predictions. On this basis, we generate autofocusing beams by combining multiple Airy beams and digital propagation. Results show that this technique can provide accurate and easy measurement of the self-accelerating characteristic in a fixed plane, as well as flexible manipulation without translating the target.

不同编码方法生成圆对称艾里光束的实验研究及其特性比较

不同编码方法生成圆对称艾里光束的实验研究及其特性比较

Curved volume waveguides induced by Airy beams in negative polarizability nanosuspensions

In this paper, we theoretically analyze the formation of stable curved volume waveguides with nonlinear optical induction by Airy beams in colloidal nanosuspensions with negative polarizability. Numerical simulations are performed to show how to modify the waveguide structures by actively control of the conditions for Airy beam generation, including the truncation factor, transverse scale, and launching direction. Possible applications of such curved waveguides are discussed.

Simultaneous generation of high-power, ultrafast 1D and 2D Airy beams and their frequency-doubling characteristics.

We report on a simple experimental scheme based on a pair of cylindrical lenses (convex and concave) of the same focal length and common optical elements, producing high power optical beams in 1D and/or 2D Airy intensity profiles with laser polarization as the control parameter. Using an ultrafast Yb-fiber laser at 1064nm of average power of 5W in a Gaussian spatial profile and pulse width of ∼180 fs, we have generated 1D and 2D Airy beams at an efficiency of 80% and 70%, respectively, and a pulse width of ∼188 and ∼190 fs, respectively. We have measured the transverse deflection rate of 1D and 2D beams to be ∼5.0×10-5 1/mm and ∼2.0×10-5 1/mm, respectively. Simply rotating the polarization state of the 1D cubic phase modulated beam in the experiment, we can produce 1D and 2D Airy beams on demand. Using a 5mm long bismuth borate (BiB3O6), we have also studied frequency-doubling characteristics of both 1D and 2D Airy beams. Like the 2D Airy beam, the 1D Airy beam also produces a frequency-doubled 1D Airy and an additional 1D spatial cubic structure. Like the Gaussian beams, we have observed the focusing dependence of conversion efficiency for both 1D and 2D Airy beams, producing green 1D and 2D Airy beams of output powers in excess of 110 and 150mW for 3.4 and 2.8W of fundamental power, respectively.

Generation of high-quality tunable Airy beams with an adaptive deformable mirror

Self-accelerating Airy beams have emerged to hold great promise in wide applications due to their non-diffraction and self-healing characteristics. The generation of Airy beams with high quality and high efficiency still remains challenging for conventional diffractive or refractive optical elements. In this Letter, tunable Airy beams with high quality are realized using a reflective adaptive deformable mirror (DM). Both the controllable cubic phase and the compensatory phase for aberrations of the optical system are generated simultaneously to ensure high quality of the resultant Airy beam. Continuous cubic phases with different amplitudes and rotation angles can be readily generated, demonstrating exceptional tunability of the generated Airy beams using a DM device. The intensity profiles and propagation trajectories of the experimentally generated Airy beams are in good agreement with the theoretical results. Benefiting from the intrinsic superiority of a DM with high reflectivity and a high damage threshold, our proposed method for dynamic generation of Airy beams opens up an avenue to plenty of applications such as ultrahigh-power laser shaping, laser fabrication, and optical manipulation.

Microwave-controlled airy beam propagation in multilevel atomic vapors

The propagation of two-dimensional Airy beams through an atomic system in closed-Λ configuration is theoretically investigated in which the hyperfine levels are coupled by a microwave pulse. Based on the generalized Huygens-Fresnel integral, the analytical expression for Airy beam through three-level atomic vapor is presented. By utilizing the S-matrix, the susceptibility determined by the microwave field, can play an important role to control Airy beam properties such as acceleration, self-bending and the intensity distribution, in the multi-level atomic systems. The mechanism of efficient manipulation of an Airy beam may have important applications in signal processing and optical communication.

Generation of colorful Airy beams and Airy imaging of letters via two-photon processed cubic phase plates.

In this Letter, we demonstrate the observation of colorful Airy beams and Airy imaging of letters, which we called Airy letters here, generated through the continuous cubic phase microplate (CCPP) elaborately fabricated by femtosecond laser two-photon processing. The fabricated CCPP with both micro size (60 μm×60 μm×1.1 μm) and continuous variation of phase shows a good agreement with the designed CCPP.Chromatic Airy beams and Airy letters "USTC" are experimentally generated via the CCPP illuminated by white light. In addition, superior properties of Airy letters are explored, demonstrating that the Airy letters inherit the nondiffraction, self-healing, and transverse acceleration characteristics of Airy beams. Our work paves the way toward integrated optics, light separation, optical imaging, and defective information recovery.

Airy beams on two dimensional materials

We propose that quasi-transverse-magnetic (quasi-TM) Airy beams can be supported on two dimensional (2D) materials. By taking graphene as a typical example, the solution of quasi-TM Airy beams is studied under the paraxial approximation. The analytical field intensity in a bilayer graphene-based planar plasmonic waveguide is confirmed by the simulation results. Due to the tunability of the chemical potential of graphene, the self-accelerating behavior of the quasi-TM Airy beam can be steered effectively. 2D materials thus provide a good platform to investigate the propagation of Airy beams.

自加速艾里光束的生成及控制

自加速艾里光束的生成及控制

Anomalous Reflection of Acoustic Waves in Air with Metasurfaces at Low Frequency

An acoustic metasurface made of a composite structure of cavity and membrane is proposed and numerically investigated. The target frequency is in the low frequency regime (570 Hz). The unit cells, which provide precise local phase modulation, are rather thin with thickness in the order around 1/5 of the working wavelength. The numerical simulations show that the designed metasurface can steer the reflected waves at will. By taking the advantage of this metasurface, an ultrathin planar acoustic axicon, acoustic lens, and acoustic nondiffracting Airy beam generator are realized. Our design method provides a new approach for the revolution of future acoustic devices.

Simultaneous Airy beam generation for both surface plasmon polaritons and transmitted wave based on metasurface.

Based on the amplitude and phase modulation of subwavelength slits, a metasurface which can simultaneously generate Airy beam for surface plasmon polaritons (SPPs) and transmitted wave is presented. Interestingly, by changing the handedness of circularly polarized light, the position of SPPs Airy beam can be switched to the left or right side of the metasurface, while the field distribution and the position of the Airy beam for transmitted wave are not affected. The nondiffracting, self-bending and self-healing properties of the generated Airy beams are analyzed as well. In addition, abruptly autofocusing of SPPs and transmitted wave are demonstrated by interfering two Airy beams. The dual functionality and chirality features of the metasurface can provide more freedoms in the potential applications of Airy beams.

Propagation of Airy beams in the quadratic-index medium based on matrix optics

We investigate the propagation of the Airy beam in the quadratic-index medium based on matrix optics. It shows there is a periodic beam profile change induced by the inhomogeneity of medium, which displays the periodic change of the field distribution from the Airy profile to the Gaussian profile. We also know the duration time of the Gaussian profile of the beam is determined by the decay factor of the Airy beam. Yet, the accelerating trajectory of the Airy beam is independent of decay factor of the Airy beam. Moreover, we show that the beam size of the Gaussian profile is different for the Airy beam with the different decay factor.

Design, transform and control of optical field in discrete optical system: an example

A discrete optical system can broaden the spatial distribution of the input light through optical coupling in array waveguides, just like diffraction in continuous media. Here, we theoretically demonstrate several kinds of control methods of optical field propagation in a discrete optical system, which is composed of an Airy fiber with two perpendicular arrayed cores. A brief transform mechanism between Gaussian and Airy beam propagation in such a fiber is presented. The wavefront of the output beam from the Airy fiber is actually dependent on the phased arrayed modulation of coupling array cores. Except the optical wavelength changing, we propose two new methods, including fiber length and bending-induced refractive-index changing, to accomplish that modulation. The calculation results show that these new methods are very effective for the Airy phase modulation. By combining these methods and controlling the corresponding parameters, the Gaussian beam, the one-dimension Airy beam, and the two-dimension Airy beam can be obtained by one same Airy fiber. These methods are also generally applicable to the other discrete optical system and can be extended to generate any other types of optical beams, such as Bessel beams and Mathieu beams.

Suppression of collapse for two-dimensional Airy beam in nonlocal nonlinear media

Dynamics and collapse of two-dimensional Airy beams are investigated numerically in nonlocal nonlinear media with split step Fourier transform method. In particular, the stability and self-healing properties of the Airy beams depend crucially on the location and topological charge of the vortex when the beams carry angular momentum. The propagation of abruptly autofocusing Airy beams is also demonstrated in local and nonlocal media. In strongly self-focusing regime, with the help of nonlocality, stationary propagation of two-dimensional Airy beams can be obtained, which always collapse in local nonlinear media.

Continuous cubic phase microplates for generating high-quality Airy beams with strong deflection.

Owing to the distinguishing properties of nondiffraction, self-healing, and transverse acceleration, Airy beams have attracted much attention in the past decade. To date, a simple approach for exquisitely fabricating cubic phase plates with both continuous variation of phase and micro size still remains challenging, which limits the generation of high-quality Airy beams for integrated micro-optics. Here, we report the elaborate design and fabrication of a continuous cubic phase microplate (CCPP) for generating high-quality Airy beams in micrometer scale. A CCPP with a precise size (60 μm×60 μm×1.1 μm) is fabricated by femtosecond laser direct writing, exhibiting a high optical efficiency (∼79%). The high-quality Airy beam generated via the CCPP demonstrates an unprecedentedly strong deflection (∼4.2 μm within a 90μm propagation distance) as well as being diffraction-free. Our research on the design and fabrication of miniature Airy phase plates paves the way toward high-performance integrated optics, optical micromanipulation, and optical imaging.