scholarly journals Shortcuts to Adiabaticity for Optical Beam Propagation in Nonlinear Gradient Refractive-Index Media

Entropy ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 673 ◽  
Author(s):  
Qian Kong ◽  
Huimin Ying ◽  
Xi Chen
Keyword(s):  
Refractive Index ◽  
Beam Propagation ◽  
Beam Width ◽  
Adiabatic Compression ◽  
Optical Beam ◽  
Variational Approximation ◽  
Adiabatic Process ◽  
Auxiliary Equation ◽  
Shortcuts To Adiabaticity ◽  
Gradient Refractive Index

In recent years, the concept of “shortcuts to adiabaticity" has been originally proposed to speed up sufficiently slow adiabatic process in various quantum systems without final excitation. Based on the analogy between classical optics and quantum mechanics, we present a study on fast non-adiabatic compression of optical beam propagation in nonlinear gradient refractive-index media by using shortcuts to adiabaticity. We first apply the variational approximation method in nonlinear optics to derive the auxiliary equation for connecting the beam width with the refractive index of the medium. Then, the gradient refractive index is inversely designed through the perfect compression of beam width with the appropriate boundary conditions. Finally, the comparison with conventional adiabatic compression is made, showing the advantage of our shortcuts.

Beam propagation in gradient refractive-index media

1992 ◽  
Vol 31 (25) ◽  
pp. 5201 ◽  
Author(s):  
G. N. Lawrence ◽  
S.-H. Hwang
Keyword(s):  
Refractive Index ◽  
Beam Propagation ◽  
Gradient Refractive Index

scholarly journals Low Side Lobe Tapered Slot Antenna with High Gain Using Gradient Refractive Index Metamaterial for Ultra Wideband Application

2017 ◽  
Vol 6 (4) ◽  
pp. 63-69 ◽  
Author(s):  
R. Singha ◽  
D. Vakula
Keyword(s):  
Refractive Index ◽  
Beam Width ◽  
Parallel Line ◽  
Side Lobe ◽  
High Gain ◽  
Ultra Wideband ◽  
Slot Antenna ◽  
Side Lobe Level ◽  
Beam Focusing ◽  
Gradient Refractive Index

A broadband gradient refractive index (GRIN) metamaterial is used to improve the gain of the tapered slot antenna. The proposed metamaterial is capable of reducing the side lobe level of the antenna. The gradient refractive index (GRIN) metamaterial is constructed by using non-resonant parallel-line unit cells with different refractive index. Due to the non-resonant structure, the proposed unit cell exhibits low loss and large frequency bandwidth. The metamaterial, whose effective refractive index is lower than that of the substrate on which the antenna is printed. Therefore, the proposed metamaterial is act as a regular lens in beam focusing. The GRIN metamaterial is integrated in front of the antenna which has the capability to manipulate electromagnetic wave accurately. The measurement results indicate that the reflection coefficient of the antenna is below -10 dB over the frequency band from 3 to 11 GHz. The radiation pattern of the antenna shows the beam width becomes narrow and directive with low side lobe level. The peak gain is increased by 2.1 dB at 9.5 GHz.

scholarly journals Energy Transfer Using Gradient Index Metamaterial

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Boopalan Ganapathy ◽  
Subramaniam Chittur Krishnaswamy
Keyword(s):  
Refractive Index ◽  
Energy Transfer ◽  
Spherical Wave ◽  
Beam Width ◽  
Horn Antenna ◽  
Index Structure ◽  
Side Lobe Level ◽  
Antenna Aperture ◽  
Gradient Refractive Index ◽  
Directive Gain

The gradient refractive index structure in this paper is used to increase the quantum of energy transfer. This is done by improving the directive gain of the pyramidal horn antenna at a frequency of 10 GHz. A three-dimensional array of closed square rings is placed in front of the horn antenna aperture to form a gradient refractive index structure. This structure increases the directive gain by 1.6 dB as compared to that of the conventional horn antenna. The structure nearly doubles the wireless power transfer quantum between the transmitter and the receiver when placed at both ends. The increase in the directivity is achieved by converting the spherical wave emanating from the horn to a plane wave once it passes through the structure. This transformation is realized by the gradient refractive index structure being placed perpendicular to the direction of propagation. The gradient refractive index is constructed by changing the dimensions of a closed square ring placed in the unit cell of the array. The change in the refractive index gives rise to an improvement of the half power beam width and side lobe level compared to that of the normal horn. The design and simulation were done using CST Studio software.

scholarly journals Tunable Optical Beam Deflection Via Liquid Crystal Gradient Refractive Index Generated By Highly Resistive Polymer Film

2016 ◽  
Vol 8 (3) ◽  
pp. 1-11 ◽  
Author(s):  
Xiaobing Shang ◽  
Ailee Mae Trinidad ◽  
Pankaj Joshi ◽  
Jelle De Smet ◽  
Dieter Cuypers ◽  
...  
Keyword(s):  
Refractive Index ◽  
Liquid Crystal ◽  
Polymer Film ◽  
Optical Beam ◽  
Beam Deflection ◽  
Gradient Refractive Index

Gradient refractive-index optical rod prepared from methacrylate derivatives

1997 ◽  
Vol 22 (10) ◽  
pp. 668 ◽  
Author(s):  
Jui-Hsiang Liu ◽  
Hung-Tsai Liu
Keyword(s):  
Refractive Index ◽  
Gradient Refractive Index

Hybrid Polymers for Gradient Refractive Index Lens

2021 ◽  
Author(s):  
Omena Okpowe ◽  
Andriy Durygin ◽  
Vadym Drozd ◽  
Temitayo Olowu ◽  
Nezih Pala ◽  
...  
Keyword(s):  
Refractive Index ◽  
Hybrid Polymers ◽  
Gradient Refractive Index

scholarly journals The Polymerization of MMA and ST to Prepare Material with Gradient Refractive Index in Electric Field

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Yao Huang ◽  
Daming Wu ◽  
Dongyun Ren ◽  
Qingyun Meng ◽  
Xiaojun Di
Keyword(s):  
Molecular Weight ◽  
Refractive Index ◽  
Electric Field ◽  
Cylindrical Sample ◽  
Electrical Field ◽  
Molecular Weights ◽  
The Matrix ◽  
Gradient Refractive Index ◽  
Scattering Material ◽  
Different Parts

Light scattering material with gradient refractive index was prepared under the electrical field by taking methyl methacrylate (MMA) monomer as the matrix with the addition of a little preheated styrene (ST) and peroxidation benzoin formyl (BPO). The material obtained under electrical field presented different transmittance and molecular weight at different parts of the cylindrical sample along the axis of the direction of electric field which led to the layering phenomenon and gradient refractive index. The disparity of molecular weight between different layers can be as much as 230 thousand. There were several peaks in the figure of GPC test of the sample under electric field. This proved that there were polymers with different molecular weights in the sample. Therefore, it can be concluded that electrical field has a significant effect on polymerization.

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