Pinhole Zone Plate Lens for Ultrasound Focusing

Fuster, J.M.; Castiñeira-Ibáñez, Sergio; Rubio, Constanza; Belmar, Francisco; Candelas, Pilar

doi:10.3390/s17071690

Cited by 15 publications

(11 citation statements)

References 20 publications

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“…All measures were done using an automated full-precision measurement system in order to validate and compare both lenses. This system consisted of a fixed ultrasonic transducer and a 3D positioned hydrophone [49], which granted precise and reliable results with 1 × 1 mm2 scanning. The transducer used in this experiment was a 250-kHz Imasonic piston with 32 mm of active diameter, and the needle hydrophone was an MPM1/1 from Precision Acoustic Ltd. made of polyvinylidene fluoride with a diameter of 1.5 mm.…”

Section: Resultsmentioning

confidence: 99%

Design of Acoustical Bessel-Like Beam Formation by a Pupil Masked Soret Zone Plate Lens

Tarrazó-Serrano

Castiñeira-Ibáñez

Minin

et al. 2019

Sensors

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The image performance of acoustic and ultrasound sensors depends on several fundamental parameters such as depth of focus or lateral resolution. There are currently two different types of acoustic diffractive lenses: those that form a diffraction-limited spot with a shallow depth of focus (zone plates) and lenses that form an extended focus (quasi-Bessel beams). In this paper, we investigate a pupil-masked Soret zone plate, which allows the tunability of a normalized angular spectrum. It is shown that the depth of focus and the lateral resolution can be modified, without changing the lens structure, by choosing the size of the pupil mask. This effect is based on the transformation of spherically-converging waves into quasi-conical waves, due to the apodization of the central part of the zone plate. The theoretical analysis is verified with both numerical simulations and experimental measurements. A Soret zone plate immersed in water with D/2F = 2.5 and F = 4.5λ changes its depth of focus from 2.84λ to 5.9λ and the lateral resolution increases from 0.81λ to 0.64λ at a frequency of 250 kHz, by modifying the pupil mask dimensions of the Soret zone plate.

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Section: Resultsmentioning

confidence: 99%

Design of Acoustical Bessel-Like Beam Formation by a Pupil Masked Soret Zone Plate Lens

Tarrazó-Serrano

Castiñeira-Ibáñez

Minin

et al. 2019

Sensors

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“…The focusing of waves has always attracted much scientific interest because of its applications in different physic areas, such as optics, microwave propagation, and acoustics [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. To achieve wave focusing, devices based on both refraction and diffraction mechanisms can be used.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Fresnel Zone Plates Focusing Dependence on Operating Frequency

Fuster

Candelas

Castiñeira-Ibáñez

et al. 2017

Sensors

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The focusing properties of Fresnel Zone Plates (FZPs) against frequency are analyzed in this work. It is shown that the FZP focal length depends almost linearly on the operating frequency. Focal depth and focal distortion are also considered, establishing a limit on the frequency span at which the operating frequency can be shifted. An underwater FZP ultrasound focusing system is demonstrated, and experimental results agree with the theoretical analysis and simulations.

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“…All the measures have been done using an automated full precision measurement system in order to validate and compare the proposed lenses. This well-know system consists in a fixed ultrasonic transducer and a 3D positioned hydrophone [46]. This systems grants precise and reliable results with…”

Section: Resultsmentioning

confidence: 99%

Design of Acoustical Bessel-Like Beam Formation by Tunable Angular Spectrum in Soret Zone Plate Lens

Tarrazó-Serrano¹,

Castiñeira-Ibáñez²,

Minin³

et al. 2018

Preprint

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The image performance of acoustic and ultrasound sensors depends on several fundamental parameters such as depth of focus or spatial resolution. There are currently two different type of acoustic diffractive lenses: those which form a diffraction-limited spot with a shallow depth of focus (zone plates) and lenses which form an extended focus (quasi-Bessel beams). In this paper, we investigate a pupil-masked Soret zone plate which allows the tunability of a normalized angular spectrum. It is shown that the depth of focus and the spatial resolution can be modified, without changing the lens structure, by choosing the size of the amplitude pupil mask. This effect is based on the transformation of spherically converging waves into quasi-conical waves, due to the apodization of the central part of the zone plate. The theoretical analysis is verified with both numerical simulations and experimental measurements. A Soret zone plate immersed in water with D/2F=2.5 and F=4.5$\lambda$, changes its depth of focus from 2.84$\lambda$ to 5.9$\lambda$ and the spatial resolution increases from 0.81$\lambda$ to 0.64$\lambda$ at a frequency of 250 kHz, by modifying the pupil mask dimensions of the Soret zone plate.

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Pinhole Zone Plate Lens for Ultrasound Focusing

Cited by 15 publications

References 20 publications

Design of Acoustical Bessel-Like Beam Formation by a Pupil Masked Soret Zone Plate Lens

Design of Acoustical Bessel-Like Beam Formation by a Pupil Masked Soret Zone Plate Lens

Analysis of Fresnel Zone Plates Focusing Dependence on Operating Frequency

Design of Acoustical Bessel-Like Beam Formation by Tunable Angular Spectrum in Soret Zone Plate Lens

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