SAS Autofocus Based on Phase Gradient Autofocus

2011 ◽  
Author(s):  
Sanwen Zhu ◽  
Jianping Yue ◽  
Weitao Jiang
Keyword(s):  
Phase Gradient

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

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

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

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.

scholarly journals High-Efficiency, Dual-Band Beam Splitter Based on an All-Dielectric Quasi-Continuous Metasurface

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3184
Author(s):  
Jing Li ◽  
Yonggang He ◽  
Han Ye ◽  
Tiesheng Wu ◽  
Yumin Liu ◽  
...  
Keyword(s):  
Wavelength Range ◽  
Conversion Efficiency ◽  
Antenna Arrays ◽  
Beam Splitter ◽  
High Efficiency ◽  
Visible Region ◽  
Polarized Light ◽  
Dual Band ◽  
Phase Gradient ◽  
Total Transmission

Metasurface-based beam splitters attracted huge interest for their superior properties compared with conventional ones made of bulk materials. The previously reported designs adopted discrete metasurfaces with the limitation of a discontinuous phase profile. In this paper, we propose a dual-band beam splitter, based on an anisotropic quasi-continuous metasurface, by exploring the optical responses under x-polarized (with an electric field parallel to the direction of the phase gradient) and y-polarized incidences. The adopted metasurface consists of two identical trapezoidal silicon antenna arrays with opposite spatial variations that lead to opposite phase gradients. The operational window of the proposed beam splitter falls in the infrared and visible region, respectively, for x- and y-polarized light, resulting from the different mechanisms. When x-polarized light is incident, the conversion efficiency and total transmission of the beam splitter remains higher than 90% and 0.74 within the wavelength range from 969 nm to 1054 nm, respectively. In this condition, each array can act as a beam splitter of unequal power. For y-polarized incidence, the maximum conversion efficiency and transmission reach approximately 100% and 0.85, while the values remain higher than 90% and 0.65 in the wavelength range from 687 nm to 710 nm, respectively. In this case, each array can be viewed as an effective beam deflector. We anticipate that it can play a key role in future integrated optical devices.

scholarly journals Optical Spin Hall Effect in Closed Elliptical Plasmonic Nanoslit with Noncircular Symmetry

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 851
Author(s):  
Xiaorong Ren ◽  
Xiangyu Zeng ◽  
Chunxiang Liu ◽  
Chuanfu Cheng ◽  
Ruirui Zhang ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Hall Effect ◽  
Light Field ◽  
Analytical Calculation ◽  
Spin Hall Effect ◽  
Spin Component ◽  
Phase Gradient ◽  
Bright Spots ◽  
Principal Axes ◽  
Output Field

We investigated the optical spin Hall effect (OSHE) of the light field from a closed elliptical metallic curvilinear nanoslit instead of the usual truncated curvilinear nanoslit. By making use of the characteristic bright spots in the light field formed by the noncircular symmetry of the elliptical slit and by introducing a method to separate the incident spin component (ISC) and converted spin component (CSC) of the output field, the OSHE manifested in the spot shifts in the CSC was more clearly observable and easily measurable. The slope of the elliptical slit, which was inverse along the principal axes, provided a geometric phase gradient to yield the opposite shifts of the characteristic spots in centrosymmetry, with a double shift achieved between the spots. Regarding the mechanism of this phenomenon, the flip of the spin angular momentum (SAM) of CSC gave rise to an extrinsic orbital angular momentum corresponding to the shifts of the wavelet profiles of slit elements in the same rotational direction to satisfy the conservation law. The analytical calculation and simulation of finite-difference time domain were performed for both the slit element and the whole slit ellipse, and the evolutions of the spot shifts as well as the underlying OSHE with the parameters of the ellipse were achieved. Experimental demonstrations were conducted and had consistent results. This study could be of great significance for subjects related to the applications of the OSHE.

Analysis of radiation of antennas with a phase‐gradient partially reflective surface

2015 ◽  
Vol 9 (12) ◽  
pp. 1323-1330
Author(s):  
Hamid Moghadas ◽  
Mojgan Daneshmand ◽  
Pedram Mousavi
Keyword(s):  
Phase Gradient ◽  
Reflective Surface
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