Engineering the intensity trajectory and phase gradient of light beams

2018 ◽  
Author(s):  
Alejandra Serrano Trujillo ◽  
Víctor Ruiz Cortés
Keyword(s):  
Phase Gradient ◽  
Light Beams

scholarly journals Time-varying optical vortices enabled by time-modulated metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 2957-2976
Author(s):  
Hooman Barati Sedeh ◽  
Mohammad Mahdi Salary ◽  
Hossein Mosallaei
Keyword(s):  
Indium Tin Oxide ◽  
Topological Charge ◽  
Communication Systems ◽  
Structured Light ◽  
Angular Acceleration ◽  
Optical Vortices ◽  
Time Varying ◽  
Phase Gradient ◽  
Light Beams ◽  
Frequency Gradient

AbstractIn this paper, generation of optical vortices with time-varying orbital angular momentum (OAM) and topological charge is theoretically demonstrated based on time-modulated metasurfaces with a linearly azimuthal frequency gradient. The topological charge of such dynamic structured light beams is shown to continuously and periodically change with time evolution while possessing a linear dependence on time and azimuthal frequency offset. The temporal variation of OAM yields a self-torqued beam exhibiting a continuous angular acceleration of light. The phenomenon is attributed to the azimuthal phase gradient in space-time generated by virtue of the spatiotemporal coherent path in the interference between different frequencies. In order to numerically authenticate this newly introduced concept, a reflective dielectric metasurface is modelled consisting of silicon nanodisk heterostructures integrated with indium-tin-oxide and gate dielectric layers on top of a mirror-backed silicon slab which renders an electrically tunable guided mode resonance mirror in near-infrared regime. The metasurface is divided into several azimuthal sections wherein nanodisk heterostructures are interconnected via nanobars serving as biasing lines. Addressing azimuthal sections with radio-frequency biasing signals of different frequencies, the direct dynamic photonic transitions of leaky-guided modes are leveraged for realization of an azimuthal frequency gradient in the optical field. Generation of dynamic twisted light beams with time-varying OAM by the metasurface is verified via performing several numerical simulations. Moreover, the role of modulation waveform and frequency gradient on the temporal evolution and diversity of generated optical vortices is investigated which offer a robust electrical control over the number of dynamic beams and their degree of self-torque. Our results point toward a new class of structured light for time-division multiple access in optical and quantum communication systems as well as unprecedented optomechanical manipulation of objects.

scholarly journals Phase Singularities to Polarization Singularities

2020 ◽  
Vol 2020 ◽  
pp. 1-33
Author(s):  
Ruchi ◽  
P. Senthilkumaran ◽  
Sushanta Kumar Pal
Keyword(s):  
Angular Momentum ◽  
Circular Polarization ◽  
Orbital Angular Momentum ◽  
Polarization Vector ◽  
Scalar Fields ◽  
Phase Gradient ◽  
Phase Singularities ◽  
Light Beams

Polarization singularities are superpositions of orbital angular momentum (OAM) states in orthogonal circular polarization basis. The intrinsic OAM of light beams arises due to the helical wavefronts of phase singularities. In phase singularities, circulating phase gradients and, in polarization singularities, circulating ϕ12 Stokes phase gradients are present. At the phase and polarization singularities, undefined quantities are the phase and ϕ12 Stokes phase, respectively. Conversion of circulating phase gradient into circulating Stokes phase gradient reveals the connection between phase (scalar) and polarization (vector) singularities. We demonstrate this by theoretically and experimentally generating polarization singularities using phase singularities. Furthermore, the relation between scalar fields and Stokes fields and the singularities in each of them is discussed. This paper is written as a tutorial-cum-review-type article keeping in mind the beginners and researchers in other areas, yet many of the concepts are given novel explanations by adopting different approaches from the available literature on this subject.

A Modified Phase Gradient Autofocus (PGA) Algorithm for Airborne/Stationary Bistatic SAR Imaging

2014 ◽  
Vol 35 (6) ◽  
pp. 1456-1463
Author(s):  
Song Zhou ◽  
Min Bao ◽  
Shi-chao Chen ◽  
Meng-dao Xing ◽  
Zheng Bao
Keyword(s):  
Phase Gradient ◽  
Bistatic Sar ◽  
Sar Imaging

Self-Localization of Light Beams in a Medium with Instantaneous Kerr Nonlinearity Switching

2020 ◽  
Vol 131 (5) ◽  
pp. 679-688
Author(s):  
S. E. Savotchenko
Keyword(s):  
Kerr Nonlinearity ◽  
Light Beams

Phase unwrapping based on the phase‐gradient‐jump connections

2017 ◽  
Vol 53 (10) ◽  
pp. 683-685 ◽  
Author(s):  
Tao Zhang ◽  
Xiaolei Lv ◽  
Jiang Qian ◽  
Jun Hong ◽  
Ye Yun
Keyword(s):  
Phase Unwrapping ◽  
Phase Gradient

EPR light beams and non-Gaussian quantum distributions in the time domain

2009 ◽  
Vol 6 (7) ◽  
pp. 577-580
Author(s):  
N. H. Adamyan ◽  
H. H. Adamyan ◽  
G. Yu. Kryuchkyan
Keyword(s):  
Time Domain ◽  
Non Gaussian ◽  
The Time Domain ◽  
Light Beams ◽  
Quantum Distributions

scholarly journals Wavefront shaping and modulation with resonant electro-optic phase gradient metasurfaces

2021 ◽  
Vol 118 (7) ◽  
pp. 071104
Author(s):  
D. Barton ◽  
M. Lawrence ◽  
J. Dionne
Keyword(s):  
Phase Gradient ◽  
Electro Optic ◽  
Wavefront Shaping

Triple Bragg Diffraction of Bessel Light Beams by Ultrasound in Uniaxial Crystals

2021 ◽  
Author(s):  
G. V. Kulak ◽  
S. V. Kulakov ◽  
P. I. Ropot ◽  
O. V. Shakin
Keyword(s):  
Bragg Diffraction ◽  
Light Beams ◽  
Bessel Light Beams

scholarly journals On-chip trans-dimensional plasmonic router

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3357-3365 ◽  
Author(s):  
Shaohua Dong ◽  
Qing Zhang ◽  
Guangtao Cao ◽  
Jincheng Ni ◽  
Ting Shi ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Incident Angle ◽  
Reciprocal Lattice ◽  
Plasmonic Waveguide ◽  
Optical Diffraction ◽  
Local Dynamic ◽  
Phase Gradient ◽  
On Chip ◽  
Plasmon Polaritons

AbstractPlasmons, as emerging optical diffraction-unlimited information carriers, promise the high-capacity, high-speed, and integrated photonic chips. The on-chip precise manipulations of plasmon in an arbitrary platform, whether two-dimensional (2D) or one-dimensional (1D), appears demanding but non-trivial. Here, we proposed a meta-wall, consisting of specifically designed meta-atoms, that allows the high-efficiency transformation of propagating plasmon polaritons from 2D platforms to 1D plasmonic waveguides, forming the trans-dimensional plasmonic routers. The mechanism to compensate the momentum transformation in the router can be traced via a local dynamic phase gradient of the meta-atom and reciprocal lattice vector. To demonstrate such a scheme, a directional router based on phase-gradient meta-wall is designed to couple 2D SPP to a 1D plasmonic waveguide, while a unidirectional router based on grating metawall is designed to route 2D SPP to the arbitrarily desired direction along the 1D plasmonic waveguide by changing the incident angle of 2D SPP. The on-chip routers of trans-dimensional SPP demonstrated here provide a flexible tool to manipulate propagation of surface plasmon polaritons (SPPs) and may pave the way for designing integrated plasmonic network and devices.

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