Subwavelength beam focusing using a ball-shaped lens for ultrasound imaging
Autor: | Santos, Victor H. S., Lima, Everton B., Baggio, Andre L., Lopes, Jose H., Silva, Glauber T. |
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Rok vydání: | 2020 |
Předmět: | |
Druh dokumentu: | Working Paper |
Popis: | Ultrasonic superresolution images can be generated by means of (super) focusing acoustic beams to subwavelength dimensions or using algorithm-based methods. Here, we demonstrate that ultrasonic pulses which are superfocused by a ball-shaped lens can be used to produce superresolution images. The imaging system is comprised of a circular flat transducer with an operation frequency of $1$ MHz, and a ball lens centered in the beam axis of symmetry. The corresponding wavelength in water is ${\lambda}_0 = 1.53$ mm. The system resolution is $0.6{\lambda}_0$ in the focal plane at one wavelength away from the lens. The superresolution method is compared with a conventional ultrasonic system based on a spherically focused transducer. Our method presents twice more resolution with a shorter depth-of-field of $2{\lambda}_0$. Possible applications that take advantage of these features are discussed, as well as some limitations of the proposed technique. Comment: 15 pages, 7 figures |
Databáze: | arXiv |
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