Electromagnetic Vortices

4 Chapter 4Figure 4.1 Schematic diagram of spatial transformation.Figure 4.2 Schematic diagram of FDM printing technology.Figure 4.3 Schematic diagram of SLA printing technology.Figure 4.4 Schematic diagram of Polyjet printing technology.Figure 4.5 Schematic representation of the spatial transformation from virtu...Figure 4.6 Several combinations for generating different modes of vortex wav...Figure 4.7 Phase and far‐field distributions for different mode lenses at 12...Figure 4.8 Phase distributions of designed devices at 8, 10, 12, 14, and 16 ...Figure 4.9 Numerical simulation results for the OAM generation device with m...Figure 4.10 (a) Experimental measurement setup of the proposed device in a m...Figure 4.11 Measured performances at 8, 10, 12, 14, and 16 GHz. (a) Phase di...Figure 4.12 Schematic principle of the spatial transformation for designing ...Figure 4.13 (a) Permittivity curve of the engineered unit cells; (b) photogr...Figure 4.14 Photograph of the fabricated prototype of the microstrip patch a...Figure 4.15 Results of OAM array antennas used as a feeding source to illumi...Figure 4.16 Simulation results of OAM array antennas (without lens) and lens...Figure 4.17 Phase distributions at 10 GHz for different topological modes ( l Figure 4.18 Schematic principle illustrating the near‐field measurement setu...Figure 4.19 Reflection coefficient responses of different feeds in presence ...Figure 4.20 Measured electric near‐field amplitude distributions in the xoy ...Figure 4.21 Measured near electric field phase distributions from 6 to 14 GH...Figure 4.22 Measured electric near‐field amplitude distributions at differen...Figure 4.23 Measured near electric field amplitude distributions in the xoz ...Figure 4.24 (a–e) Far‐field normalized radiation patterns without lens and w...Figure 4.25 Purity mode spectrum at 10 GHz. (a) Feeding source alone; (b) le...Figure 4.26 Illustration demonstrating the omnidirectional radiation process...Figure 4.27 Quasi‐conformal mapping from virtual domain to physical domain o...Figure 4.28 E‐field amplitude distribution in the x−z plane for an ope...Figure 4.29 Simulated far‐field radiation patterns of the different lens‐ant...Figure 4.30 Simulated phase distributions of the EM field component in the x ...

5 Chapter 5Figure 5.1 Illustration of the vectorial electric field distributions in the...Figure 5.2 PS representation of the states‐of‐polarization of a plane wave....Figure 5.3 Higher‐order PS representation of the states‐of‐polarization of v...Figure 5.4 (a) Unit cell configuration and (b) the homogenized multilayer an...Figure 5.5 (a) Simulated CP transmission as a function of frequency for the Figure 5.6 (a) Configuration and (b) schematics of diffraction of a supercel...Figure 5.7 (a) Unit cell configuration and (b) the homogenized multilayer an...Figure 5.8 CP (a) transmission and (b) reflection magnitudes of the Q ‐band g...Figure 5.9 Contour plots of simulated T LRand T RRas a function of both freq...Figure 5.10 Simulated (solid lines) and analytically (circles) calculated ph...Figure 5.11 (a) Unit cell configuration; (b) the first (fourth) and second (...Figure 5.12 Distribution of the simulated (a) cross‐polarized CP transmissio...Figure 5.13 (a) Steps for calculating the far‐field properties of the transm...Figure 5.14 (a) Distribution of the rotation angle ( ϕ r) of the Ka ‐band ...Figure 5.15 Normalized measured LCP and RCP components of the far‐field (a) ...Figure 5.16 Simulated and measured efficiency of the transmit‐array as a fun...Figure 5.17 Conceptual configurations of the geometric‐phase transmit‐array ...Figure 5.18 (a) Normalized simulated orthogonally‐polarized component of the...Figure 5.19 Schematics illustrating the use of a single geometric‐phase tran...Figure 5.20 (a) Cell rotation angle distribution ϕ r( x , y ) and (b) a pho...Figure 5.21 Normalized (a) measured and (b) calculated intensity patterns fo...Figure 5.22 (a) Cell rotation angle distribution ϕ r( x , y ) and (b) a pho...Figure 5.23 Normalized measured intensity patterns for different polarizatio...Figure 5.24 Phase delay distributions for both (a) ϕ LR( x , y ) and (b) ϕ ...Figure 5.25 (a) Normalized calculated intensity patterns for different polar...

6 Chapter 6Figure 6.1 (a–c) Intensity of an OAM beam with topological charge ℓ = −1, 0,...Figure 6.2 Examples of macroscopic vortex generating devices: (a) spiral pha...Figure 6.3 Metasurfaces for OAM beams generation [20,45–49].Figure 6.4 (a) Metamaterials applications in automobile industry [57]....Figure 6.5 Wavefront, intensity profiles, and interference patterns with a G...Figure 6.6 Applications of OAM beams. (a) Optical trapping [83].(b) nano...Figure 6.7 (a) Schematic of shared‐aperture phased array; (b) scanning elect...Figure 6.8 (a) Schematics of the proposed beam deflector with the unit cell ...Figure 6.9 Reconfigurable metasurfaces: (a) electrically tunable [89],(b...Figure 6.10 (a) Working principle of nonlinear metasurface with reconfigurab...Figure 6.11 From passive to active integrated OAM sources: (a) integrated OA...Figure 6.12 Spatial hole burning suppression and OAM lasing in a ring cavity...Figure 6.13 (a) Lasing characterization; (b) input–output laser curve, showi...Figure 6.14 (a) Measured chirality of laser emissions as a function of time ...Figure 6.15 Schematic of (a) a conventional liquid crystal in the nematic ph...Figure 6.16 (a) A three‐dimensional model of an MDOE designed to produce orb...Figure 6.17 Colloidal suspensions offer a unique platform for engineering op...Figure 6.18 Experimental setup (a) and results showing the formation of the ...

7 Chapter 7Figure 7.1 The phase distribution of an optical vortex beam for different to...Figure 7.2 The intensity (a–c) and the corresponding phase distribution (d–f...Figure 7.3 (a) The diagram of SPP.(b) a vortex beam generated by SPP.Figure 7.4 A fork‐shaped diffraction grating produced by computer simulation...Figure 7.5 The sketch of the fork‐shaped hologram that can produce many diff...Figure 7.6 (a) Layout structures of the SZP; (b) Binarized SZP.Figure 7.7 Experimentally measured intensity profile of different circular o...Figure 7.8 (a) Schematic setup of DMD based microlithography.(b) microgr...Figure 7.9 Schematic diagram of: (a) converter; (b) π converter.Figure 7.10 Schematics of the generation of compound vortex beams with oppos...Figure 7.11 (a) Experimental setup based on metasurfaces for generating and ...Figure 7.12 (a) SEM image of plasmonic metasurface (F2) with topological cha...Figure 7.13 The 2‐D experimental pattern of the perfect vortex beams with ρ 0Figure 7.14 The experimental results of the perfect vortex beams with radius...Figure 7.15 Generation of perfect vortex beams through Fourier transformatio...Figure 7.16 Notation and coordinates for a helicodal phase step. [60].Figure 7.17 A density plot of the paraxial wave | ψ α= 2.2| in the ...Figure 7.18 Layout structures of CGH for producing fractional vortex beams. ...Figure 7.19 Normalized 3D amplitude distribution (top), contour graph for th...Figure 7.20 The notation of the spiral slit for achieving an anomalous Besse...Figure 7.21 Intensity and the phase patterns of vortex beams with the differ...

8 Chapter 8Figure 8.1 Schematic presentation of a scatterer that rotates at an angle of...Figure 8.2 Schematic and the response of the ultrathin complementary metasur...Figure 8.3 The composite PEC–PMC metasurfaces for OAM generation. (a) l = 1....Figure 8.4 The quadrupole‐ xy and quadrupole‐diag states (amplitude patterns)...Figure 8.5 A schematic representation of OAM generation in PCs.Figure 8.6 The experimental verification of the proposed PC. (a) Experimenta...Figure 8.7 Analysis of the radiated EM wave from UCAs. (a) Configuration of ...Figure 8.8 The extracted mode amplitudes along with the radial coordinates a...Figure 8.9 Schematic representation of multiple OAM‐beam detections by using...Figure 8.10 Full‐wave simulated far‐field power patterns when the incident w...Figure 8.11 Overview of the relevant parameters in the model: the sum‐freque...Figure 8.12 Comparisons of SF and SH scattering patterns with the nonlinear ...Figure 8.13 Amplitudes and phases of the near‐field longitudinal‐field compo...Figure 8.14 Schematic of the nonlinear spin‐orbital AM coupling induced by S...Figure 8.15 SH conversion efficiencies of chiral clusters illuminated by LCP...Figure 8.16 Multipolar decompositions of the fundamental and SH scattered wa...