Jingge Wang

Propagation properties of cosh-Airy beams

We theoretically investigate the propagation properties of cosh-Airy beams, which can be considered as a superposition of two Airy beams with different decay factors. We find that the field distribution of cosh-Airy beams is the same as that of Airy beams. Moreover, we find that the evolution of cosh-Airy beams is determined by the parameters of the cosh modulation function, in addition to the transverse scale factor and decay factor of the Airy beams. Our results demonstrate a possible method of manipulating Airy beams in free space. They can also be extended to the study of the propagation properties of cosine-Airy beams (or sine-Airy beams).

In situ measurement of the topological charge of a perfect vortex using the phase shift method

We propose a method to determine the topological charge (TC) of a perfect vortex. With the phase shift technique, the perfect vortex and its conjugate beam exactly overlap and interfere. Consequently, the TC of a perfect vortex is determined by counting the number of interference fringes. This proposed method enables in situ determination of the TC of the perfect vortex without the need for additional optical elements, and it is immune to environmental vibration and parasitic interference.

Fraunhofer diffraction of Laguerre–Gaussian beam caused by a dynamic superposed dual-triangular aperture

Abstract. We investigate the Fraunhofer diffraction of a Laguerre–Gaussian (LG) beam incident on a dynamic superposed dual-triangular aperture. The evolution of the diffraction pattern from this aperture is analyzed experimentally and theoretically. A special aperture, called the hex-star triangular aperture, demonstrates interesting diffraction patterns. Further, the diffraction properties of integer, half-integer, and fractional orders of topological charges at the Fraunhofer zone are studied by using the hex-star triangular aperture. This study can provide additional information to enhance the understanding of the diffraction properties of the LG beam transmitted through a complex aperture.

Propagation of the Airy beam along the optical axis of a uniaxial medium

Abstract We investigate the propagation of an Airy beam along the optical axis of a uniaxial medium, and we find that the propagation property of the Airy beam is determined by the ordinary refractive index of uniaxial crystals and is independent of the ratio of the extraordinary to ordinary refractive index. We also know that the polarization state of linearly polarized Airy beams changes gradually during the propagation. This shows that the propagation properties of the Airy beam in uniaxial crystals along the optical axis is distinctly different from that orthogonal to the optical axis.

Airy-like electron plasma wave

In this paper, an Airy-like electron plasma wave is investigated in an unmagnetized collisionless plasma consisting of inertial electrons and static ions. Just like the optical Airy beam, the Airy-like electron plasma wave also has two interesting propagation characteristics: it has transverse acceleration and is diffraction-free, which display that the Airy-like electron plasma wave propagates along a curved trajectory and retains the basic structure for longer distances in the propagation direction, respectively. We give a numerical simulation for the electrostatic potential of the Airy-like electron plasma wave and show that, with the increase of the propagation distance, the electrostatic potential decreases in the propagation direction but increases in the transverse direction.

The spin Hall effect of light in moving medium

In this paper, we investigate the spin Hall effect of light in moving inhomogeneous medium using the Gordon metric and the Maxwell’s equations in the gravitational field. Light experiences a moving medium as a gravitational field by means of the Gordon metric. It is shown that the spin Hall effect of light is modified by the motion of medium, and the deflection of the ray trajectory is dependent on the polarization and the motion of the medium. It is interesting that there is no coupling of the spin angular momentum of light and the effective gravitational field when the medium is moving along the direction of the gradient ∇n(r). The results provide a potential method for controlling the spin Hall effect of light in medium.

Close-packed optical vortex lattices with controllable structures

As a spatial structured light field, the optical vortex (OV) has attracted extensive attention in recent years. In practice, the OV lattice (OVL) is an optimal candidate for applications of orbital angular momentum (OAM)-based optical communications, microparticle manipulation, and micro/nanofabrication. However, traditional methods for producing OVLs meet a significant challenge: the OVL structures cannot be adjusted freely and form a close-packed arrangement, simultaneously. To overcome these difficulties, we propose an alternative scheme to produce close-packed OVLs (CPOVLs) with controllable structures. By borrowing the concept of the close-packed lattice from solid-state physics, CPOVLs with versatile structures are produced by using logical operations of expanding OV primitive cells combined with the technique of phase mask generation. Then, the existence of OAM states in the CPOVLs is verified. Furthermore, the energy flow and OAM distribution of the CPOVLs are visualized and analyzed. From a light field physics viewpoint, this work increases the adjustment dimensions and extends the fundamental understanding of the OVL, which will introduce novel applications.