Influence of Polarization Direction on Polarization States Distribution of Polarization Encoder

Author(s):  
Yu Xin ◽  
Muchun Zhou ◽  
Qi Zhao ◽  
Yanru Chen
Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 66
Author(s):  
Yuchen Wang ◽  
Hongsheng Li ◽  
Shu Hu ◽  
Heng Li ◽  
Chuanxiang Sheng

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.


Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
Qaisar Hayat ◽  
Junping Geng ◽  
Xianling Liang ◽  
Ronghong Jin ◽  
Sami Ur Rehman ◽  
...  

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.


2021 ◽  
Vol 103 (3) ◽  
Author(s):  
Ran Yang ◽  
Cheng-Jie Zhang ◽  
Jian Li ◽  
Yan-Xiao Gong ◽  
Shi-Ning Zhu

2008 ◽  
Vol 17 (04) ◽  
pp. 387-394 ◽  
Author(s):  
XIUDONG SUN ◽  
XUECONG LI ◽  
JIANLONG ZHANG

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.


2021 ◽  
Author(s):  
Xue‐Feng Wang ◽  
Xiao‐Jie Sun ◽  
Yuan‐Xing Liu ◽  
Wei Wang ◽  
Bao‐Xi Kan ◽  
...  

2014 ◽  
Vol 602-605 ◽  
pp. 3359-3362
Author(s):  
Chun Li Zhu ◽  
Jing Li

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.


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