scholarly journals Application of Fresnel Zone Plate Focused Beam to Optimized Sensor Design for Pulse-Echo Harmonic Generation Measurements

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1373 ◽  
Author(s):  
Hyunjo Jeong ◽  
Hyojeong Shin ◽  
Shuzeng Zhang ◽  
Xiongbing Li ◽  
Sungjong Cho

In nonlinear acoustic measurements involving reflection from the stress-free boundary, the pulse-echo method could not be used because such a boundary is known to destructively change the second harmonic generation (SHG) process. The use of a focusing acoustic beam, however, can improve SHG after reflection from the specimen boundary, and nonlinear pulse-echo methods can be implemented as a practical means of measuring the acoustic nonlinear parameter (β) of solid specimens. This paper investigates the optimal sensor design for pulse-echo SHG and β measurements using Fresnel zone plate (FZP) focused beams. The conceptual design of a sensor configuration uses separate transmission and reception, where a broadband receiver is located at the center and a four-element FZP transmitter is positioned outside the receiver to create a focused beam at the specified position in a solid sample. Comprehensive simulations are performed for focused beam fields analysis and to determine the optimal sensor design using various combinations of focal length, receiver size and frequency. It is shown that the optimally designed sensors for 1 cm thick aluminum can produce the second harmonic amplitude and the uncorrected nonlinear parameter corresponding to the through-transmission method. The sensitivity of the optimal sensors to the changes in the designed sound velocity is analyzed and compared between the odd- and even-type FZPs.

2019 ◽  
Vol 1 (2) ◽  
pp. 117-125
Author(s):  
Hyunjo Jeong ◽  
Shu-zeng Zhang ◽  
Xiong-bing Li

Abstract In nonlinear acoustic harmonic generation in solids with stress-free boundaries, such a boundary is known to destructively change the second harmonic generation, and the pulse-echo method is not practically applicable. Focused beams have often been used for fluid nonlinearity and biomechanical imaging in pulse-echo test setups. This paper considers the focused beam fields of linear phased-array transducers to ensure that pulse-echo harmonic generation can be applied to solids with stress-free boundaries. The fundamental and second-harmonic beam fields that are focused and reflected at the stress-free and rigid boundaries are calculated and their properties are investigated in terms of the received average fields. The phase difference between the two second-harmonic components after reflection from the boundary—that is, the reflected and the newly generated second harmonic—is emphasized. The phase difference is used to explain the improved and accumulated second harmonic observed in the simulation results.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Yoshio Suzuki ◽  
Akihisa Takeuchi ◽  
Hisataka Takenaka ◽  
Ikuo Okada

A Fresnel zone plate (FZP) with 35 nm outermost zone width has been fabricated and tested in the hard X-ray region. The FZP was made by electron beam lithography and reactive ion etching technique. The performance test of the FZP was carried out by measuring the focused beam profile for coherent hard X-ray beam at the beamline 20XU of SPring-8. The full width at half maximum of the focused beam profile measured by knife-edge scan method is 34.9±2.7 nm, that agrees well with the theoretical value of diffraction-limited resolution. Applications to scanning microscopy were also carried out.


Author(s):  
Daniel Jandura ◽  
Dusan Pudis ◽  
Tomas Mizera ◽  
Marek Vevericik ◽  
Peter Gaso

2021 ◽  
Vol 92 (2) ◽  
pp. 023701 ◽  
Author(s):  
Akihisa Takeuchi ◽  
Kentaro Uesugi ◽  
Masayuki Uesugi ◽  
Hiroyuki Toda ◽  
Kyosuke Hirayama ◽  
...  

1994 ◽  
Vol 109 (3-4) ◽  
pp. 324-327 ◽  
Author(s):  
Yu.A. Basov ◽  
D.V. Roshchupkin ◽  
A.E. Yakshin

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