Generation of spatial Bessel beams using holographic metasurface

Abstract

We propose to use backward radiations of leaky waves supported by a holographic metasurface to produce spatial Bessel beams in the microwave frequency regime. The holographic metasurface consists of a grounded dielectric slab and a series of metal patches. By changing the size of metal patches, the surface-impedance distribution of the holographic metasurface can be modulated, and hence the radiation properties of the leaky waves can be designed to realize Bessel beams. Both numerical simulations and experiments verify the features of spatial Bessel beams, which may be useful in imaging applications or wireless power transmissions with the dynamic focal-depth controls.

A new class of nondiffracting pulses based on focusing leaky waves

“…However, whenâ r increases [see Figs 2 (b)-2(d)], the electric field exhibits an exponential decay, which limits the intensity of the field more and more as long as the leakage rateâ r increases. This is in agreement with the experimental results recently reported in [18]. On one hand, it is seen that for small leakage rates, i.e.,â r ≤ 0.01 (see Figs 2(b) and 2(c)), the impact ofâ r is even beneficial to 'smooth' the beam from the diffractive behavior of the field outside the diamond-shaped region (see Fig.…”

Multifunctional metasurface: from extraordinary optical transmission to extraordinary optical diffraction in a single structure

“…Resorting to the abrupt phase change of each resonant element instead of accumulated interaction with large coherent length between light and structure, ultrathin metasurface can provide various applications, such as beam deflection [7][8][9][10][11], focusing [12][13][14][15][16], complex beam shaping [17][18][19][20][21], holographic display [22][23][24][25][26], and multiplexed hologram recording [27][28][29][30][31][32][33][34][35][36]. Generally, the previous metasurface can only work on either transmission mode [7] or reflection mode [9,25] depending on deterministic decaying pathway of its resonance.…”

Dual-Axis Metasurface Strain Sensor Based on Polarization–Phase-Deformation Relationship

“…In the last decade, metamaterials (MM) have revealed the attractive capabilities for electromagnetic (EM) properties manipulation enabled by artificial structures, and have achieved several exotic and otherwise impossible functionalities such as negative refraction [1][2][3], cloaking [4][5][6], and perfect absorption [7][8][9]. As the two-dimensional simplified form of MM, metasurfaces (MS) [10] have shown unique advantages for the control of the phase, magnitude, and polarization of EM waves, and have been widely applied in wavefront shaping [11][12][13], holographic imaging [14][15][16], and superlensing [17][18][19]. Over the wide frequency range from the microwave to optical bands, MMs and MSs provide an effective and feasible strategy for the manipulation of EM propagation through an appropriate arrangement of meta-atoms that has been a focus of EM research.…”