Multistatic impulse radar reconstructing for the arbitrary incident polarization direction

1990 ◽  
Author(s):  
Ma Xincai ◽  
Feng Kongyu
Keyword(s):  
Polarization Direction ◽  
Incident Polarization

scholarly journals Crystalline Orientation Identification of Phosphorene Using Polarized Raman Spectroscopy without Analyzer

2019 ◽  
Vol 9 (11) ◽  
pp. 2198 ◽  
Author(s):  
Hua-Qiang Bao ◽  
Ru-Bing Li ◽  
Hua-Dan Xing ◽  
Chuan Qu ◽  
Qiu Li ◽  
...  
Keyword(s):  
Crystal Orientation ◽  
Accurate Method ◽  
Rapid Identification ◽  
Polarization Direction ◽  
Crystalline Orientation ◽  
Photoelectric Properties ◽  
Parallel Polarization ◽  
Polarized Raman Spectroscopy ◽  
Polarized Raman ◽  
Incident Polarization

The unique photoelectric properties of phosphorene typically include anisotropy, hence the nondestructive and rapid identification of its crystal orientation is a key point to the investigation and application of phosphorene. Currently, the orientation identification by analyzing the Ag1 mode based on parallel-polarized Raman has severe requirements for the applicable Raman system. Therefore, it is necessary to develop a more general, convenient, and accurate method for determining the crystal orientation of phosphorene. In this paper, a method of orientation identification was proposed by using a Raman system without an analyzer and quantifying the correlation between the intensities of Ag1 and Ag2 modes with the change of the incident polarization direction. By using mechanically peeled phosphorene as specimens, Raman measurements were carried out under the Raman configurations of both parallel polarization and with no analyzer. The results show that the crystal orientation of phosphorene can be accurately identified by quantifying the Raman intensities of both Ag1 and Ag2 modes using the Raman system without an analyzer.

scholarly journals Unusual Polarization Relation between Single-Mode Lasing Emission and Excitation Laser from an Evanescent-Wave Pumped Micro-Cavity Laser

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 66
Author(s):  
Yuchen Wang ◽  
Hongsheng Li ◽  
Shu Hu ◽  
Heng Li ◽  
Chuanxiang Sheng
Keyword(s):  
Evanescent Wave ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Ethanol Solution ◽  
Pump Laser ◽  
Fiber Axis ◽  
Lasing Threshold ◽  
Polarization Direction ◽  
Excitation Laser ◽  
Output Laser

Using a fiber of that is 125 μm in diameter in rhodamine 6G ethanol solution, controllable multi- and single-whispering-gallery-mode (WGM) optofluidic lasers based on evanescent-wave-coupled gain are both available. With multi-mode WGM emission, lasing emission with almost pure TM (transverse magnetic) or almost TE (transverse electric) modes can be obtained when the pump laser has an electric field parallel (perpendicular) to the fiber axis, i.e., the polarization direction of output laser is the same as that of the pump laser. On the other hand, when the laser emission is single-mode, the TE output laser always emerges firstly above lasing threshold, then keeps TE mode while the pump laser’s intensity increases with polarization direction perpendicular to the fiber axis; on the contrary, TE emission will dwindle relatively, while the TM emission emerges and dominates the spectra, when the pump laser’s intensity increases with polarization parallel to the fiber axis. Our work proves that controlling the leakage of the evanescent wave from high-Q microcavities is crucial for both modes of lasing emission and its polarization.

scholarly journals Core-Shell Nano-Antenna Configurations for Array Formation with More Stability Having Conventional and Non-Conventional Directivity and Propagation Behavior

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Qaisar Hayat ◽  
Junping Geng ◽  
Xianling Liang ◽  
Ronghong Jin ◽  
Sami Ur Rehman ◽  
...  
Keyword(s):  
Plane Wave ◽  
Propagation Direction ◽  
Core Shell ◽  
Incident Plane Wave ◽  
Polarization Direction ◽  
Shell Nanoparticles ◽  
Incident Plane ◽  
Core Shell Nanoparticles ◽  
Coated Nanoparticle ◽  
2D Array

The enhancement of optical characteristics at optical frequencies deviates with the choice of the arrangement of core-shell nanoparticles and their environment. Likewise, the arrangements of core-shell nanoparticles in the air over a substrate or in liquid solution makes them unstable in the atmosphere. This article suggests designing a configuration of an active spherical coated nanoparticle antenna and its extended array in the presence of a passive dielectric, which is proposed to be extendable to construct larger arrays. The issue of instability in the core-shell nanoantenna array models is solved here by inserting the passive dielectric. In addition to this, the inclusion of a dielectric in the array model reports a different directivity behaviour than the conventional array models. We found at first that the combination model of the active coated nanoparticle and passive sphere at the resonant frequency can excite a stronger field with a rotated polarization direction and a propagation direction different from the incident plane-wave. Furthermore, the extended 2D array also rotates the polarization direction and propagation direction for the vertical incident plane-wave. The radiation beam operates strong multipoles in the 2D array plane at resonant frequency (behaving non-conventionally). Nevertheless, it forms a clear main beam in the incident direction when it deviates from the resonance frequency (behaving conventionally). The proposed array model may have possible applications in nano-amplifiers, nano-sensors and other integrated optics.

ORIENTATING MANIPULATION OF CYLINDRICAL PARTICLES WITH OPTICAL TWEEZERS

2008 ◽  
Vol 17 (04) ◽  
pp. 387-394 ◽  
Author(s):  
XIUDONG SUN ◽  
XUECONG LI ◽  
JIANLONG ZHANG
Keyword(s):  
Escherichia Coli ◽  
Carbon Nanotubes ◽  
Laser Beam ◽  
Optical Tweezers ◽  
Optical Trap ◽  
Polarization Direction ◽  
Beam Shape ◽  
E Coli ◽  
Potential Applications ◽  
Cylindrical Particles

Orientating manipulations of cylindrical particles were performed by optical tweezers. Vertical and horizontal manipulations of Escherichia coli (E. coli) were carried out by changing the trapping depth and the focused laser beam shape. It was found that carbon nanotubes bundles (CNTBs) could be rotated in the linear polarized optical trap until it orientated its long axis along the linear polarization direction of the laser beam. However, E.coli could not be orientated in this way. Corresponding mechanisms were discussed based on the anisomeric electric characters of CNTBs. These orientation technologies of cylindrical objects with optical trap have potential applications in assembling nano-electric devices.

Three-Dimensional Finite-Difference Time-Domain Method Modeling of Nanowire Optical Probe

2014 ◽  
Vol 602-605 ◽  
pp. 3359-3362
Author(s):  
Chun Li Zhu ◽  
Jing Li
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Incident Light ◽  
Near Field ◽  
Three Dimensional ◽  
Polarization Direction ◽  
Near Field Imaging ◽  
Difference Time ◽  
Field Imaging

In this paper, output near fields of nanowires with different optical and structure configurations are calculated by using the three-dimensional finite-difference time-domain (3D FDTD) method. Then a nanowire with suitable near field distribution is chosen as the probe for scanning dielectric and metal nanogratings. Scanning results show that the resolution in near-field imaging of dielectric nanogratings can be as low as 80nm, and the imaging results are greatly influenced by the polarization direction of the incident light. Compared with dielectric nanogratings, metal nanogratings have significantly enhanced resolutions when the arrangement of gratings is perpendicular to the polarization direction of the incident light due to the enhancement effect of the localized surface plasmons (SPs). Results presented here could offer valuable references for practical applications in near-field imaging with nanowires as optical probes.

scholarly journals Current-Induced Spin Photocurrent in GaAs at Room Temperature

Sensors ◽  
2022 ◽  
Vol 22 (1) ◽  
pp. 399
Author(s):  
Yang Zhang ◽  
Yu Liu ◽  
Xiao-Lan Xue ◽  
Xiao-Lin Zeng ◽  
Jing Wu ◽  
...  
Keyword(s):  
Electric Field ◽  
Spin Polarization ◽  
Applied Electric Field ◽  
Room Temperature ◽  
Polarization Direction ◽  
Applied Bias ◽  
Applied Bias Voltage ◽  
Sample Plane ◽  
Bulk Gaas ◽  
Circularly Polarized

Circularly polarized photocurrent, observed in p-doped bulk GaAs, varies nonlinearly with the applied bias voltage at room temperature. It has been explored that this phenomenon arises from the current-induced spin polarization in GaAs. In addition, we found that the current-induced spin polarization direction of p-doped bulk GaAs grown in the (001) direction lies in the sample plane and is perpendicular to the applied electric field, which is the same as that in GaAs quantum well. This research indicates that circularly polarized photocurrent is a new optical approach to investigate the current-induced spin polarization at room temperature.

Controlling the interference between localized and delocalized surface plasmons via incident polarization for optical switching

2018 ◽  
Vol 32 (16) ◽  
pp. 1850194
Author(s):  
Wen-Bo Song ◽  
Yun Qi ◽  
Xiao-Peng Zhang ◽  
Ming-Li Wan ◽  
Jinna He
Keyword(s):  
Surface Plasmons ◽  
Optical Switching ◽  
Electromagnetically Induced Transparency ◽  
Ground Plane ◽  
Photonic Devices ◽  
Biochemical Sensors ◽  
Optical Responses ◽  
Surface Enhanced Raman ◽  
Induced Transparency ◽  
Incident Polarization

Surface plasmons supported by various metallic nanostructures have given rise to several significant breakthroughs in the field of integrated photonic devices due to its ability to effectively confine and enhance optical field in subwavelength volume. In particular, the demand to actively control optical responses of plasmonic systems becomes urgent for the miniaturization of signal processing devices, surface-enhanced Raman scattering (SERS) substrates and biochemical sensors. In this paper, we systematically investigate the plasmon modes as well as their interaction in a layered nanostructure composed of a periodically-arranged radiative nanoring and a metallic ground plane, as well as a thin insulating spacer. A tunable transparent peak on the background of the broadband plasmon resonance emerges in the reflection spectrum as changing the periodicity of nanoparticle array, a plasmonic analogue of electromagnetically induced transparency (EIT). Owing to the structural symmetry of the rings, we demonstrate a new scheme of controlling the interference between localized and delocalized plasmons by means of incident polarization and believe that the proposed metasurface may find applications in optical switching if the polarization-controlled components are introduced.

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