scholarly journals Electrically tunable absorber based on a graphene integrated lithium niobate resonant metasurface

2021 ◽  
Author(s):  
Xingqiao Chen ◽  
Qi Meng ◽  
wei xu ◽  
Jianfa Zhang ◽  
Zhu Hong ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Tunable Absorber

Raman spectroscopy and X-ray diffraction of lithium niobate at temperatures up to 1300○-4.80pt○C

2005 ◽  
Vol 126 ◽  
pp. 101-105 ◽  
Author(s):  
B. Moulin ◽  
L. Hennet ◽  
D. Thiaudière ◽  
P. Melin ◽  
P. Simon
Keyword(s):  
Raman Spectroscopy ◽  
Lithium Niobate ◽  
X Ray Diffraction ◽  
X Ray

Growth and Characterization of High Homogeneity Heavily MgO-doped Lithium Niobate Crystals

2011 ◽  
Vol 25 (12) ◽  
pp. 1257-1262 ◽  
Author(s):  
Xiao-Niu TU ◽  
Yan-Qing ZHENG ◽  
Hui CHEN ◽  
Hai-Kuan KONG ◽  
Jun XIN ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
High Homogeneity ◽  
Lithium Niobate Crystals

Nanocomposite Graphene based Tunable Absorber for Combating Electromagnetic Pollution

2019 ◽  
Vol 15 ◽  
Author(s):  
Surekha Rani ◽  
Anupma Marwaha ◽  
Sanjay Marwaha
Keyword(s):  
Reflection Coefficient ◽  
Traffic Congestion ◽  
Microwave Absorber ◽  
Electromagnetic Properties ◽  
Electric Conductor ◽  
High Frequency Structure Simulator ◽  
Bias Potential ◽  
External Bias ◽  
Tunable Microwave ◽  
Tunable Absorber

Background: Advancement in wireless communication technology has raised today’s living standards but consequently leads to the problems of electromagnetic (EM) air pollution as well as spectrum congestion particularly in radio frequency band. To overcome traffic congestion problem in lower bands, terahertz frequency bands are explored but EM pollution still persists as global issue which can be addressed by a tunable microwave absorber. At THz frequencies, 2-D nanostructured graphene has been observed to be less lossy than using other materials and further finds its most interesting applications on account of the plasmonic mode supported by graphene resulting in extreme device miniaturization. At micro and mm-waves graphene is resistive hence can be electronically controlled, ensuring its suitability for the design of tunable microwave absorber. Objective: Designing of a frequency reconfigurable or frequency tunable absorber is the prime objective of current work. Two-dimensional graphene absorber has been proposed here having inherent bandgap tunability property which means the electromagnetic properties of graphene can be controlled via varying external bias potential. Methods: The numerical modelling of graphene microwave absorber utilizing bulk graphene backed by glass and perfect electric conductor layer is reported in this paper. Finite element Method (FEM) based high frequency structure simulator (HFSS) platform is used to simulate the graphene absorber model. The whole structure is placed into a rectangular waveguide with two ports for absorber excitation. Results: The variation of electromagnetic properties of graphene absorber is achieved by changing bias potential and further the absorption tunability for the designed absorber is investigated in the range from 2 GHz to 18 GHz. From reflection coefficient curves, it is authenticated that -72.6 dB reflection coefficient dip has been obtained at 14 GHz for 5 volt bias potential which shifts to higher side of frequency as the potential changes from 5 volts to 25 volts. Conclusion: The results show that by increasing bias potential, absorption coefficient shifts to higher frequency and proves to be a tunable wideband absorber whose resonant frequency can changed from one value to another without changing thickness or material properties of absorber thus can effectively incorporate with antenna substrate or surface of radar.

Formation of Regular Domain Structures in Quenched Ferroelectrics Under the Influence of an External High-frequency Electric Field

2019 ◽  
Vol 9 (3) ◽  
pp. 344-352 ◽  
Author(s):  
L.I. Stefanovich ◽  
O.Y. Mazur ◽  
V.V. Sobolev
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Domain Structure ◽  
High Frequency ◽  
Evolution Equations ◽  
Regular Domain ◽  
Field Frequency ◽  
Domain Structures ◽  
Alternating Electric Field ◽  
Lithium Niobate Crystals

Introduction: Within the framework of the phenomenological theory of phase transitions of the second kind of Ginzburg-Landau, the kinetics of ordering of a rapidly quenched highly nonequilibrium domain structure is considered using the lithium tantalate and lithium niobate crystals as an example. Experimental: Using the statistical approach, evolution equations describing the formation of the domain structure under the influence of a high-frequency alternating electric field in the form of a standing wave were obtained. Numerical analysis has shown the possibility of forming thermodynamically stable mono- and polydomain structures. It turned out that the process of relaxation of the system to the state of thermodynamic equilibrium can proceed directly or with the formation of intermediate quasi-stationary polydomain asymmetric phases. Results: It is shown that the formation of Regular Domain Structures (RDS) is of a threshold character and occurs under the influence of an alternating electric field with an amplitude less than the critical value, whose value depends on the field frequency. The conditions for the formation of RDSs with a micrometer spatial scale were determined. Conclusion: As shown by numerical studies, the RDSs obtained retain their stability, i.e. do not disappear even after turning off the external electric field. Qualitative analysis using lithium niobate crystals as an example has shown the possibility of RDSs formation in high-frequency fields with small amplitude under resonance conditions

Testing lithium niobate boules for integrated optics applications

1986 ◽  
Vol 22 (12) ◽  
pp. 674 ◽  
Author(s):  
G.E. Peterson ◽  
S.R. Lunt
Keyword(s):  
Lithium Niobate ◽  
Integrated Optics

scholarly journals High Field Single- to Few-Cycle THz Generation with Lithium Niobate

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 183
Author(s):  
Xing Zhu ◽  
David R. Bacon ◽  
Julien Madéo ◽  
Keshav M. Dani
Keyword(s):  
Lithium Niobate ◽  
Condensed Matter ◽  
High Harmonic ◽  
Nonlinear Spectroscopy ◽  
Optical Rectification ◽  
Phase Matching ◽  
Nonlinear Phenomena ◽  
Generation Efficiency ◽  
Basic Principles ◽  
Thz Generation

The transient terahertz (THz) pulse with high peak field has become an important tool for matter manipulation, enabling many applications such as nonlinear spectroscopy, particle acceleration, and high harmonic generation. Among the widely used THz generation techniques, optical rectification in lithium niobate (LN) has emerged as a powerful method to achieve high fields at low THz frequencies, suitable to exploring novel nonlinear phenomena in condensed matter systems. In this review, we focus on introducing single- to few-cycle THz generation in LN, including the basic principles, techniques, latest developments, and current limitations. We will first discuss the phase matching requirements of LN, which leads to Cherenkov-like radiation, and the tilted pulse front (TPF) technique. Emphasis will be put on the TPF technique, which has been shown to improve THz generation efficiency, but still has many limitations. Different geometries used to produce continuous and discrete TPF will be systematically discussed. We summarize the advantages and limitations of current techniques and future trends.

scholarly journals Probing Rotated Weyl Physics on Nonlinear Lithium Niobate-on-Insulator Chips

2021 ◽  
Vol 127 (1) ◽  
Author(s):  
Zhi-Wei Yan ◽  
Qiang Wang ◽  
Meng Xiao ◽  
Yu-Le Zhao ◽  
Shi-Ning Zhu ◽  
...  
Keyword(s):  
Lithium Niobate

The input of Barkhausen pulses to the switching current in congruent lithium niobate

2021 ◽  
Vol 574 (1) ◽  
pp. 156-163
Author(s):  
I. A. Kipenko ◽  
A. R. Akhmatkhanov ◽  
A. A. Esin ◽  
V. Ya. Shur
Keyword(s):  
Lithium Niobate ◽  
Switching Current ◽  
Congruent Lithium Niobate
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