scholarly journals The Peculiarities of the Acoustic Waves of Zero-Order Focusing in Lithium Niobate Plate

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4000
Author(s):  
Iren Kuznetsova ◽  
Ilya Nedospasov ◽  
Andrey Smirnov ◽  
Vladimir Anisimkin ◽  
Dmitry Roshchupkin ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
Electric Fields ◽  
Acoustic Waves ◽  
Transfer Functions ◽  
Lamb Waves ◽  
Zero Order ◽  
Beam Focusing ◽  
Acoustic Beams ◽  
Hybrid Devices ◽  
Shear Horizontal

In this research, beam focusing in lithium niobate plate was studied for fundamental anti-symmetric (A0) and symmetric (S0) Lamb waves, and the shear-horizontal (SH0) wave of zero-order. Using the finite element method, appropriate configuration of the interdigital transducer with arc-like electrodes was modeled accounting for the anisotropy of the slowness curves and dispersion of the modes in the plate. Profiles of the focalized acoustic beams generated by the proposed transducer were theoretically analyzed. Based on the result of the analysis, relevant delay lines were fabricated and transfer functions (insertion loss) of the line were measured for SH0 wave in YX-lithium niobate plate. Using an electron scanning microscope, distribution of the electric fields of the same wave were visualized. The results of this study may be useful for hybrid devices and sensors combining nano and acoustoelectronic principles.

Enhancing responses of Lamb waves to bias electric fields by flexoelectricity

2021 ◽  
pp. 1-14
Author(s):  
Sihao Lv ◽  
Wenjun Yang ◽  
Qian Deng ◽  
Shengping Shen
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Strain Gradient ◽  
Acoustic Waves ◽  
Lamb Waves ◽  
Gradient Elasticity ◽  
High Sensitivity ◽  
Strain Gradient Elasticity ◽  
Voltage Sensors ◽  
Bias Electric Field

Abstract In this work, responses of Lamb waves to a bias electric field in a nanoplate with the consideration of piezoelectricity, flexoelectricity, and strain gradient elasticity are investigated. Firstly, governing equations and boundary conditions of acoustic waves propagating in bias fields are derived. Then, dispersion equations under a bias electric field are obtained and solved numerically. Numerical solutions indicate that flexoelectricity can enhance the response of Lamb waves to external bias electric fields. It is also found that the competition between flexoelectricity and strain gradient elasticity leads to a complex variation of the voltage sensitivity with respect to the wavelength and frequency of Lamb waves. Our work may provide a way of resolving the contradiction between high sensitivity and miniaturization in the conventional voltage sensors based on surface acoustic waves. The theoretical results can guide a new design of voltage sensors with high sensitivity.

Attenuation of Surface Acoustic Waves by Carbon Nanotubes

2002 ◽  
Vol 750 ◽  
Author(s):  
Daumantas Ciplys ◽  
Sergey Rumyantsev ◽  
Michael S. Shur ◽  
Robert Vajtai ◽  
Bingqing Wei ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Lithium Niobate ◽  
Single Crystal ◽  
Electric Fields ◽  
Acoustic Waves ◽  
Qualitative Agreement ◽  
Surface Acoustic Waves ◽  
Charge Carriers ◽  
Lithium Niobate Single Crystal

ABSTRACTA strong attenuation of surface acoustic waves in the range of 30 to 100 MHz by singlewalled carbon nanotube layers deposited on the surface of piezoelectric lithium niobate single crystal has been observed. The attenuation exhibits non-monotonous dependence on nanotube density. This attenuation is attributed to the acoustoelectronic interaction between electric fields of the SAW and charge carriers in the nanotubes. The experimental results are in the qualitative agreement with the theory of acoustoelectronic interaction in inhomogeneous structures.

scholarly journals Frequency-domain study of nonthermal gigahertz phonons reveals Fano coupling to charge carriers

2020 ◽  
Vol 6 (51) ◽  
pp. eabd4540
Author(s):  
Thomas Vasileiadis ◽  
Heng Zhang ◽  
Hai Wang ◽  
Mischa Bonn ◽  
George Fytas ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Acoustic Waves ◽  
Lamb Waves ◽  
Charge Carriers ◽  
Acoustic Phonons ◽  
Phonon Spectra ◽  
Electron Hole Plasma ◽  
Nonequilibrium Conditions ◽  
Microelectronic Components ◽  
Anti Stokes

Telecommunication devices exploit hypersonic gigahertz acoustic phonons to mediate signal processing with microwave radiation, and charge carriers to operate various microelectronic components. Potential interactions of hypersound with charge carriers can be revealed through frequency- and momentum-resolved studies of acoustic phonons in photoexcited semiconductors. Here, we present an all-optical method for excitation and frequency-, momentum-, and space-resolved detection of gigahertz acoustic waves in a spatially confined model semiconductor. Lamb waves are excited in a bare silicon membrane using femtosecond optical pulses and detected with frequency-domain micro-Brillouin light spectroscopy. The population of photoexcited gigahertz phonons displays a hundredfold enhancement as compared with thermal equilibrium. The phonon spectra reveal Stokes–anti-Stokes asymmetry due to propagation, and strongly asymmetric Fano resonances due to coupling between the electron-hole plasma and the photoexcited phonons. This work lays the foundation for studying hypersonic signals in nonequilibrium conditions and, more generally, phonon-dependent phenomena in photoexcited nanostructures.

scholarly journals Electro-Optic Control of Lithium Niobate Bulk Whispering Gallery Resonators: Analysis of the Distribution of Externally Applied Electric Fields

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 298
Author(s):  
Yannick Minet ◽  
Hans Zappe ◽  
Ingo Breunig ◽  
Karsten Buse
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Electric Fields ◽  
Frequency Comb ◽  
Parametric Oscillation ◽  
Pockels Effect ◽  
Optical Mode ◽  
Cylindrical Resonator ◽  
Whispering Gallery ◽  
Electro Optic

Whispering gallery resonators made out of lithium niobate allow for optical parametric oscillation and frequency comb generation employing the outstanding second-order nonlinear-optical properties of this material. An important knob to tune and control these processes is, e.g., the linear electro-optic effect, the Pockels effect via externally applied electric fields. Due to the shape of the resonators a precise prediction of the electric field strength that affects the optical mode is non-trivial. Here, we study the average strength of the electric field in z-direction in the region of the optical mode for different configurations and geometries of lithium niobate whispering gallery resonators with the help of the finite element method. We find that in some configurations almost 100% is present in the cavity compared to the ideal case of a cylindrical resonator. Even in the case of a few-mode resonator with a very thin rim we find a strength of 90%. Our results give useful design considerations for future arrangements that may benefit from the strong electro-optic effect in bulk whispering gallery resonators made out of lithium niobate.

Investigation of acoustic waves in thin plates of lithium niobate and lithium tantalate

2001 ◽  
Vol 48 (1) ◽  
pp. 322-328 ◽  
Author(s):  
I.E. Kuznetsova ◽  
B.D. Zaitsev ◽  
S.G. Joshi ◽  
I.A. Borodina
Keyword(s):  
Lithium Niobate ◽  
Acoustic Waves ◽  
Lithium Tantalate ◽  
Thin Plates
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